Electrical System Guide for DIY Van Conversion

Electrical System Guide for DIY Van Conversion

DIY-Van-Electrical-Guide
Updated:

The electrical system was without a doubt the most daunting task of our DIY camper van conversion. Our goal was to design and build an off-the-grid electrical system that’s safe, reliable, simple, and intuitive (yet no compromises on functionality). After over 4 years of full-time VanLife, we’re happy to report that our system is working flawlessly, nice!

Designing and building an electrical system isn’t really straightforward, there are so many concepts to grasp: solar power, alternator charging, shore power, 12 volts, 120 volts, inverter, battery bank, etc. But with our background as engineers and full-time vanlifers, we’re in a good position to make this intimidating task within your reach and help you put the pieces together with the following guide!

We’re here to help! Here is how it goes:


Disclosure: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not.

Portrait-FarOutRide-Van

1. Van Electrical System In A Nutshell


In its simplest form, a campervan electrical system isn’t really complicated. It consists of a battery bank, loads, and charge sources:

Campervan-Electrical-System-In-A-Nutshell
Charge Source

The charge sources are the devices (solar, alternator, shore) that add energy to the battery bank.

Battery Bank

Charge sources are not available at all time! The role of the battery bank is to store energy acquired from the charge sources and release it to the loads when needed. There are typically two battery banks: the factory starter battery to start the engine and power the vehicle’s systems and the auxiliary “house” battery to power all the campervan systems (fridge, lights, fan, etc.).

Loads

The loads are the devices (fan, lights, fridge, etc.) that substract energy from the battery bank.

Modern “off-the-grid” vans typically charge with solar, alternator, and shore, and can power multiple 12V DC loads and 120V AC loads:

Modern-Vans-Electrical-System-Charge-Sources-and-Loads-2

Whoa, components quickly add up! That’s why a comprehensive wiring diagram is a must. Indeed, to make a functional electrical system, the components are assembled together in a precise way. Overcurrent devices (fuse, breaker), adequately sized wires, and quality components make for a safe and reliable system. The “master plan”, or “assembly plan” of such a system is called a wiring diagram.

Below are the wiring diagrams we engineered for our needs. The Standard version is optimized for off-the-grid and energy efficiency (that’s the design we implemented in our first build and we are still using to these days). The High-Power version is optimized for high-power devices such as induction cooktop, microwave, etc:

Cursor-Mouse Hover your cursor / click on components to learn more!

Standard

Optimized for off-the-grid / energy efficiency

KEY FEATURE:

The inverter and shore power are provided by two separate devices. No transfer switch to bypass the inverter when plugged to shore power.

MORE FEATURES:
  • BATTERY BANK: 100Ah and up (one or more batteries)
  • SOLAR: None or up to 700W
  • ALTERNATOR: None or up to 60A
  • SHORE: None or up to 80A DC
  • AC IN: 15A (normal house outlet)
  • INVERTER: None, 1000W, 1500W or 2000W
  • TRANSFER SWITCH: None
  • 120V AC Distribution Panel: None (loads are connected directly to the inverter)
CHOOSE THIS DIAGRAM IF:
  • Your build has modest 120V needs (no device above 1,650W).
  • You’re mostly off-the-grid (occasionally plug into shore power).
  • You’re tracking your budget. Some components (bus bars, cables, switch, fuses,etc.) in this diagram are cheaper (and smaller) because they’re rated for lower current.
  • Maybe you don’t need shore power or inverter at all?
MAIN
# Item Description Qty View on Amazon
1 Terminal Fuse Block with Fuse 250A Blue Sea (Catastrophic Fail Safe. Connects directly to battery post.) 1 View
2 System Switch Blue Sea (Main System Switch) 1 View
3 Bus Bar (250A, 4 studs) Blue Sea 2 View
4 Cover for Bus Bar (for 250A 4 studs) Protect the Bus Bar 2 View
5 40A Breaker/Switch, Surface Mount Between Fuse Block and Bus Bar 1 View
6 Fuse Block (12 circuits) Blue Sea (12V Distribution Panel) 1 View
7 Fuses Kit Assorted Fuses (2A 3A 5A 7.5A 10A 15A 20A 25A 30A 35A) 1 View
8 Battery Monitor Victron BMV-712 with BlueTooth 1 View
9 Cable, 2/0 AWG, 5 ft Red Between battery and Bus Bar 1 View
10 Cable, 2/0 AWG, 15 ft Black Between battery and Bus Bar + Ground 1 View
12 Lugs, 2/0 AWG Cable, 5/16″ Ring Connect to Bus Bar, Terminal Fuse Block and Battery (Pack of 5) 1 View
11 Lugs, 2/0 AWG Cable, 3/8″ Ring Connect to System Switch and Shunt (Pack of 5) 1 View
13 Cable, 8 AWG, 5 ft Black + 5 ft Red Between Bus Bar and Fuse Block 1 View
14 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring Connect to Fuse Block (Pack of 3) 1 View
15 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breaker (Pack of 3) 1 View
16 Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 3) 1 View
BATTERY
1 LiFePO4 200 Ah Battle Born LiFePO4 100 Ah 12V 2 View
2 2/0 AWG Cable in 5/16″ lugs, 1 feet Red + 1 feet Black Windy Nation Copper Cable 1 View
SOLAR
1 350W Solar NewPowa 175W Mono Panel 2 View
2 Extension Cables, 8 AWG, 15 ft Red + 15 ft Black With MC4 Connectors 1 View
3 Double Cable Entry Gland For 8 AWG or 10 AWG Cable 1 View
4 40A Breaker/Switch, Surface Mount Between Panels and MPPT Charger 1 View
5 MPPT Solar Charger Victron 100|30 SmartSolar MPPT 1 View
6 40A Breaker/Switch, Surface Mount Between MPPT Charger & Battery 1 View
7 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 3) 2 View
8 Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 3) 1 View
ALTERNATOR
1 60A Battery-to-Battery Charger (B2B) Sterling Power BB1260 1 View
2 100A Breaker/Switch, Surface Mount Blue Sea 285-Series 2 View
3 Cable, 4 AWG, 15ft Red WindyNation 1 View
4 Cable, 4 AWG, 5 ft Black WindyNation 1 View
5 Lugs, 4 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 10) 1 View
6 Lugs, 4 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 2) 1 View
SHORE
1 50A Charger Samlex SEC-1250UL 12V 1 View
2 60A Breaker/Switch, Surface Mount Between Charger and Bus Bar 1 View
3 Cable, 8 AWG, 5 ft Black + 5 ft Red WindyNation 1 View
4 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breaker (Pack of 3) 1 View
5 Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 3) 1 View
INVERTER
1 1000W Inverter Samlex PST-1000-12 PST Pure Sine 1 View
2 Remote Control for Inverter Samlex RC-15A for 600W/1000W Inverter 1 View
3 Terminal Fuse Block with Fuse 175A Blue Sea (Connects directly on the Bus Bar. To protect inverter’s cable.) 1 View
4 Cable, 2 AWG, 5 ft Black + 5 ft Red WindyNation 1 View
5 Lugs, 2 AWG Cable, 5/16″ Ring Connect to Terminal Fuse Block and Bus Bar (Pack of 10) 1 View
OPTIONAL ITEMS
1 120V AC GFCI Outlet GFCI, 20A View
2 Power Cord with open end 12AWG, 10 feet View
HARDWARE
1 8 AWG Black/Red Duplex Cable (8/2), Ancor Marine Grade 100 feet 1 View
2 10 AWG Black/Red Duplex Cable (10/2), Ancor Marine Grade 100 feet 1 View
3 12 AWG Black/Red Duplex Cable (12/2), Ancor Marine Grade 100 feet 1 View
4 14 AWG Black/Red Duplex Cable (14/2), Ancor Marine Grade 100 feet 1 View
5 16 AWG Black/Red Duplex Cable (16/2), Ancor Marine Grade 100 feet 1 View
6 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring To connect to Fuse Block (25 Pack) 1 View
7 Heat Shrink Terminal Ring, 10-12 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
8 Heat Shrink Terminal Ring, 14-16 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
9 Heat Shrink Butt Connector, Ancor Marine To connect to Loads (75 Pack Kit) 1 View
10 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Female
To connect to certain loads (i.e. 12V Sockets) , to make “removable” connections (i.e. Fridge, LEDs) and to connect cable of different gauge together (i.e. LED Dimmer) (25 Pack)
1 View
11 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Male 1 View
12 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Female 1 View
13 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Male 1 View
14 Heat Shrink Disconnect, 18-22 AWG Cable, 1/4″ Tab, Male 1 View
15 3M Scotchlok Quick Splice with Gel (14 AWG stranded) We used that to parallel our LED lights (25 Pack) 1 View
16 Heat Shrink Tubing Kit (with adhesive) To protect lug after crimping 1 View
17 Split Loom Tubing, 3/8″ diameter 25 feet To protect wire bundles 1 View
18 Split Loom Tubing, 1/2″ diameter 25 feet To protect wire bundles 1 View
19 Split Loom Tubing, 3/4″ diameter 10 feet To protect wire bundles 1 View
20 Nylon Cable Clamps Kit To secure cable/split-loom to wood 1 View
21 Zip Tie Mount with Adhesive To secure cable/split-loom to metal 1 View
22 Nylon Zip Ties Kit To secure cable/split-loom 1 View
23 Rubber Grommet Kit To protect wire from sharp edge (going through metal hole) 1 View
12V LOADS
1 Maxxair 6200K Roof Fan Fan Installation 1 Amazon
2 LED Ceiling Lights (Dimmable) 3 Amazon
3 PWM Dimmer for LED Lights, 12V, Slider 1 Amazon
4 Blue Sea 12V Socket Electrical System Guide 4 Amazon
5 Shurflo Revolution Water Pump, 3 GPM 1 Amazon
6 ON/OFF Switch for Water Pump 1 Amazon
7 Webasto Air Top 2000 STC Gasoline Heater Webasto Installation 1 Amazon
8 Propex HS2000 Propane Heater Propex Installation 1 Dealers
9 Novakool R5810 Fridge, 12V only Fridge Guide 1 Campervan-HQ
10 Sirocco ii Gimbal Fan, 12V Sirocco ii Installation/Review 1 Amazon
11 Nature’s Head Composting Toilet Toilet Installation 1 Amazon
12 Propane Solenoid Shutoff Valve 1 Amazon
13 ON/OFF Switch for Propane Solenoid 1 Amazon
High-Power

Optimized for high-power devices (induction cooktop, microwave, etc.)

KEY FEATURE:

The inverter, shore power and transfer switch are combined into a single device (Victron Multiplus).

MORE FEATURES:
  • BATTERY BANK: 200Ah and up (two or more batteries)
  • SOLAR: None or up to 700W
  • ALTERNATOR: None or up to 60A
  • SHORE: up to 120A DC
  • AC IN: 30A (campground hookup) or 15A (normal house outlet, via adapter)
  • INVERTER: 2000W or 3000W
  • TRANSFER SWITCH: Yes (automatically bypass inverter when plugged into shore)
  • 120V AC Distribution Panel: Yes (each load is protected by an appropriate breaker)
CHOOSE THIS DIAGRAM IF:
  • Your build includes any high-power device: air conditioning, induction cooktop, electric water heater, electric space heater, etc.
  • You frequently plug into shore power (serviced campgrounds).
  • You simply prefer an inverter/charger (Victron) instead of a separate inverter & battery charger.
MAIN
# Item Description Qty View on Amazon
1 Class T Fuse, 400A Blue Sea (Catastrophic Fail Safe) 1 View
2 Class T Fuse Block Blue Sea (Holds the Class T Fuse) 1 View
3 System Switch Blue Sea (Main System Switch) 1 View
4 Bus Bar (600A, 4 studs) Blue Sea 2 View
5 Cover for Bus Bar (for 600A 4 studs) Protect the Bus Bar 2 View
6 40A Breaker/Switch, Surface Mount Between Fuse Block and Bus Bar 1 View
7 Fuse Block (12 circuits) Blue Sea (12V Distribution Panel) 1 View
8 Fuses Kit Assorted Fuses (2A 3A 5A 7.5A 10A 15A 20A 25A 30A 35A) 1 View
9 Battery Monitor Victron BMV-712 with BlueTooth 1 View
10 Cable, 4/0 AWG, 5 ft Red Between battery and Bus Bar 1 View
11 Cable, 4/0 AWG, 15 ft Black Between battery and Bus Bar + Ground 1 View
13 Lugs, 4/0 AWG Cable, 5/16″ Ring Connect to Bus Bar, Terminal Fuse Block and Battery (Pack of 2) 1 View
12 Lugs, 4/0 AWG Cable, 3/8″ Ring Connect to System Switch and Shunt (Pack of 10) 1 View
14 Cable, 8 AWG, 5 ft Black + 5 ft Red Between Bus Bar and Fuse Block 1 View
15 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring Connect to Fuse Block (Pack of 3) 1 View
16 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breaker (Pack of 3) 1 View
17 Heat Shrink Terminal Ring, 8 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 3) 1 View
BATTERY
1 LiFePO4 400 Ah Battle Born LiFePO4 100 Ah 12V 4 View
2 4/0 AWG Cable in 5/16″ lugs, 1 feet Red + 1 feet Black Spartan Power 3 View
SOLAR
1 350W Solar NewPowa 175W Mono Panel 2 View
2 Extension Cables, 8 AWG, 15 ft Red + 15 ft Black With MC4 Connectors 1 View
3 Double Cable Entry Gland For 8 AWG or 10 AWG Cable 1 View
4 40A Breaker/Switch, Surface Mount Between Panels and MPPT Charger 1 View
5 MPPT Solar Charger Victron 100|30 SmartSolar MPPT 1 View
6 40A Breaker/Switch, Surface Mount Between MPPT Charger & Battery 1 View
8 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 3) 2 View
7 Heat Shrink Terminal Ring, 8 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 3) 1 View
ALTERNATOR
1 60A Battery-to-Battery Charger (B2B) Sterling Power BB1260 1 View
2 100A Breaker/Switch, Surface Mount Blue Sea 285-Series 2 View
3 Cable, 4 AWG, 15ft Red WindyNation 1 View
4 Cable, 4 AWG, 5 ft Black WindyNation 1 View
6 Lugs, 4 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 10) 1 View
5 Lugs, 4 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 2) 1 View
INVERTER/CHARGER
1 3000W Inverter/Charger Victron Multiplus 12|3000|120 1 View
2 Remote Control for Inverter Victron Digital Multi Control 200/200A GX 1 View
3 Class T Fuse, 400A Blue Sea (To protect inverter’s cable) 1 View
4 Class T Fuse Block Blue Sea (Holds the Class T Fuse) 1 View
5 Cable, 4/0 AWG, 5 ft Black + 5 ft Red Between Inverter/Charger & Bus Bars View
6 Lugs, 4/0 AWG Cable, 5/16″ Ring Connect to Inverter/Charger (Pack of 5) 1 View
7 Lugs, 4/0 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 5) 1 View
8 30A Shore Inlet Furrion 30A Marine Power Smart Inlet 1 View
9 30A AC Main Breaker Between Power Inlet and Inverter/Charger 1 View
11 10/3 AWG Triplex AC Marine Wire Between power inlet & inverter/charger 1 View
12 Lugs, 10 AWG Cable, #8 Connect to AC Main (Pack of 3) 1 View
13 Lugs, 10 AWG Cable, #10 Connect to AC Main (Pack of 3) 2 View
14 120V AC Distribution Panel (4 Positions*) Blue Sea Panel: AC Main + 4 Positions* 1 View
15 6/3 AWG Triplex AC Marine Wire Between inverter/charger & AC distribution panel 1 View
16 Lugs, 6 AWG Cable, #10 Connect to distribution panel (Pack of 10) 1 View
17 120V AC Wall Outlet GFCI, 20A 1 View
18 14/3 AWG Triplex AC Marine Wire To wire load that requires 15A or 10A breaker 1 View
19 Lugs, 14 AWG Cable, #8 Connect to distribution panel (Pack of 3) 1 View
20 Lugs, 14 AWG Cable, #10 Connect to distribution panel (Pack of 3) 1 View
OPTIONAL ITEMS
1 50A Breaker (Double-Pole) To upgrade 120V AC distribution panel to 50A instead of 30A View
2 20A Breaker For load that requires 20A breaker (e.g. A/C) View
3 10A Breaker For load that requires 10A breaker View
4 120V AC Distribution Panel (6 Positions*) *6 Positions panel is sometimes cheaper, check it! View
5 12/3 AWG Triplex AC Marine Wire To wire load that requires 20A breaker (e.g. A/C) View
6 Lugs, 12 AWG Cable, #8 Connect to AC Main (Pack of 3) 1 View
7 Lugs, 12 AWG Cable, #10 Connect to AC Main (Pack of 3) 1 View
HARDWARE
1 8 AWG Black/Red Duplex Cable (8/2), Ancor Marine Grade 100 feet 1 View
2 10 AWG Black/Red Duplex Cable (10/2), Ancor Marine Grade 100 feet 1 View
3 12 AWG Black/Red Duplex Cable (12/2), Ancor Marine Grade 100 feet 1 View
4 14 AWG Black/Red Duplex Cable (14/2), Ancor Marine Grade 100 feet 1 View
5 16 AWG Black/Red Duplex Cable (16/2), Ancor Marine Grade 100 feet 1 View
6 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring To connect to Fuse Block (25 Pack) 1 View
7 Heat Shrink Terminal Ring, 10-12 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
8 Heat Shrink Terminal Ring, 14-16 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
9 Heat Shrink Butt Connector, Ancor Marine To connect to Loads (75 Pack Kit) 1 View
10 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Female
To connect to certain loads (i.e. 12V Sockets) , to make “removable” connections (i.e. Fridge, LEDs) and to connect cable of different gauge together (i.e. LED Dimmer) (25 Pack)
1 View
11 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Male 1 View
12 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Female 1 View
13 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Male 1 View
14 Heat Shrink Disconnect, 18-22 AWG Cable, 1/4″ Tab, Male 1 View
15 3M Scotchlok Quick Splice with Gel (14 AWG stranded) We used that to parallel our LED lights (25 Pack) 1 View
16 Heat Shrink Tubing Kit (with adhesive) To protect lug after crimping 1 View
17 Split Loom Tubing, 3/8″ diameter 25 feet To protect wire bundles 1 View
18 Split Loom Tubing, 1/2″ diameter 25 feet To protect wire bundles 1 View
19 Split Loom Tubing, 3/4″ diameter 10 feet To protect wire bundles 1 View
20 Nylon Cable Clamps Kit To secure cable/split-loom to wood 1 View
21 Zip Tie Mount with Adhesive To secure cable/split-loom to metal 1 View
22 Nylon Zip Ties Kit To secure cable/split-loom 1 View
23 Rubber Grommet Kit To protect wire from sharp edge (going through metal hole) 1 View
12V LOADS
1 Maxxair 6200K Roof Fan Fan Installation 1 Amazon
2 LED Ceiling Lights (Dimmable) 3 Amazon
3 PWM Dimmer for LED Lights, 12V, Slider 1 Amazon
4 Blue Sea 12V Socket Electrical System Guide 4 Amazon
5 Shurflo Revolution Water Pump, 3 GPM 1 Amazon
6 ON/OFF Switch for Water Pump 1 Amazon
7 Webasto Air Top 2000 STC Gasoline Heater Webasto Installation 1 Amazon
8 Propex HS2000 Propane Heater Propex Installation 1 Dealers
9 Novakool R5810 Fridge, 12V only Fridge Guide 1 Campervan-HQ
10 Sirocco ii Gimbal Fan, 12V Sirocco ii Installation/Review 1 Amazon
11 Nature’s Head Composting Toilet Toilet Installation 1 Amazon
12 Propane Solenoid Shutoff Valve 1 Amazon
13 ON/OFF Switch for Propane Solenoid 1 Amazon
Optimized for Off-the-grid / Energy Efficiency
Optimized for High-Power Devices (Induction Cooktop, Microwave, etc)

Hand-Tap-Cursor Tap on each component to learn more!

Standard

Optimized for off-the-grid / energy efficiency

KEY FEATURE:

The inverter and shore power are provided by two separate devices. No transfer switch to bypass the inverter when plugged to shore power.

MORE FEATURES:
  • BATTERY BANK: 100Ah and up (one or more batteries)
  • SOLAR: None or up to 700W
  • ALTERNATOR: None or up to 60A
  • SHORE: None or up to 80A DC
  • AC IN: 15A (normal house outlet)
  • INVERTER: None, 1000W, 1500W or 2000W
  • TRANSFER SWITCH: None
  • 120V AC Distribution Panel: None (loads are connected directly to the inverter)
CHOOSE THIS DIAGRAM IF:
  • Your build has modest 120V needs (no device above 1,650W).
  • You’re mostly off-the-grid (occasionally plug into shore power).
  • You’re tracking your budget. Some components (bus bars, cables, switch, fuses,etc.) in this diagram are cheaper (and smaller) because they’re rated for lower current.
  • Maybe you don’t need shore power or inverter at all?
MAIN
# Item Description Qty View on Amazon
1 Terminal Fuse Block with Fuse 250A Blue Sea (Catastrophic Fail Safe. Connects directly to battery post.) 1 View
2 System Switch Blue Sea (Main System Switch) 1 View
3 Bus Bar (250A, 4 studs) Blue Sea 2 View
4 Cover for Bus Bar (for 250A 4 studs) Protect the Bus Bar 2 View
5 40A Breaker/Switch, Surface Mount Between Fuse Block and Bus Bar 1 View
6 Fuse Block (12 circuits) Blue Sea (12V Distribution Panel) 1 View
7 Fuses Kit Assorted Fuses (2A 3A 5A 7.5A 10A 15A 20A 25A 30A 35A) 1 View
8 Battery Monitor Victron BMV-712 with BlueTooth 1 View
9 Cable, 2/0 AWG, 5 ft Red Between battery and Bus Bar 1 View
10 Cable, 2/0 AWG, 15 ft Black Between battery and Bus Bar + Ground 1 View
12 Lugs, 2/0 AWG Cable, 5/16″ Ring Connect to Bus Bar, Terminal Fuse Block and Battery (Pack of 5) 1 View
11 Lugs, 2/0 AWG Cable, 3/8″ Ring Connect to System Switch and Shunt (Pack of 5) 1 View
13 Cable, 8 AWG, 5 ft Black + 5 ft Red Between Bus Bar and Fuse Block 1 View
14 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring Connect to Fuse Block (Pack of 3) 1 View
15 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breaker (Pack of 3) 1 View
16 Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 3) 1 View
BATTERY
1 LiFePO4 200 Ah Battle Born LiFePO4 100 Ah 12V 2 View
2 2/0 AWG Cable in 5/16″ lugs, 1 feet Red + 1 feet Black Windy Nation Copper Cable 1 View
SOLAR
1 350W Solar NewPowa 175W Mono Panel 2 View
2 Extension Cables, 8 AWG, 15 ft Red + 15 ft Black With MC4 Connectors 1 View
3 Double Cable Entry Gland For 8 AWG or 10 AWG Cable 1 View
4 40A Breaker/Switch, Surface Mount Between Panels and MPPT Charger 1 View
5 MPPT Solar Charger Victron 100|30 SmartSolar MPPT 1 View
6 40A Breaker/Switch, Surface Mount Between MPPT Charger & Battery 1 View
7 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 3) 2 View
8 Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 3) 1 View
ALTERNATOR
1 60A Battery-to-Battery Charger (B2B) Sterling Power BB1260 1 View
2 100A Breaker/Switch, Surface Mount Blue Sea 285-Series 2 View
3 Cable, 4 AWG, 15ft Red WindyNation 1 View
4 Cable, 4 AWG, 5 ft Black WindyNation 1 View
5 Lugs, 4 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 10) 1 View
6 Lugs, 4 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 2) 1 View
SHORE
1 50A Charger Samlex SEC-1250UL 12V 1 View
2 60A Breaker/Switch, Surface Mount Between Charger and Bus Bar 1 View
3 Cable, 8 AWG, 5 ft Black + 5 ft Red WindyNation 1 View
4 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breaker (Pack of 3) 1 View
5 Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ Ring Connect to Bus Bar (Pack of 3) 1 View
INVERTER
1 1000W Inverter Samlex PST-1000-12 PST Pure Sine 1 View
2 Remote Control for Inverter Samlex RC-15A for 600W/1000W Inverter 1 View
3 Terminal Fuse Block with Fuse 175A Blue Sea (Connects directly on the Bus Bar. To protect inverter’s cable.) 1 View
4 Cable, 2 AWG, 5 ft Black + 5 ft Red WindyNation 1 View
5 Lugs, 2 AWG Cable, 5/16″ Ring Connect to Terminal Fuse Block and Bus Bar (Pack of 10) 1 View
OPTIONAL ITEMS
1 120V AC GFCI Outlet GFCI, 20A View
2 Power Cord with open end 12AWG, 10 feet View
HARDWARE
1 8 AWG Black/Red Duplex Cable (8/2), Ancor Marine Grade 100 feet 1 View
2 10 AWG Black/Red Duplex Cable (10/2), Ancor Marine Grade 100 feet 1 View
3 12 AWG Black/Red Duplex Cable (12/2), Ancor Marine Grade 100 feet 1 View
4 14 AWG Black/Red Duplex Cable (14/2), Ancor Marine Grade 100 feet 1 View
5 16 AWG Black/Red Duplex Cable (16/2), Ancor Marine Grade 100 feet 1 View
6 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring To connect to Fuse Block (25 Pack) 1 View
7 Heat Shrink Terminal Ring, 10-12 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
8 Heat Shrink Terminal Ring, 14-16 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
9 Heat Shrink Butt Connector, Ancor Marine To connect to Loads (75 Pack Kit) 1 View
10 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Female
To connect to certain loads (i.e. 12V Sockets) , to make “removable” connections (i.e. Fridge, LEDs) and to connect cable of different gauge together (i.e. LED Dimmer) (25 Pack)
1 View
11 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Male 1 View
12 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Female 1 View
13 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Male 1 View
14 Heat Shrink Disconnect, 18-22 AWG Cable, 1/4″ Tab, Male 1 View
15 3M Scotchlok Quick Splice with Gel (14 AWG stranded) We used that to parallel our LED lights (25 Pack) 1 View
16 Heat Shrink Tubing Kit (with adhesive) To protect lug after crimping 1 View
17 Split Loom Tubing, 3/8″ diameter 25 feet To protect wire bundles 1 View
18 Split Loom Tubing, 1/2″ diameter 25 feet To protect wire bundles 1 View
19 Split Loom Tubing, 3/4″ diameter 10 feet To protect wire bundles 1 View
20 Nylon Cable Clamps Kit To secure cable/split-loom to wood 1 View
21 Zip Tie Mount with Adhesive To secure cable/split-loom to metal 1 View
22 Nylon Zip Ties Kit To secure cable/split-loom 1 View
23 Rubber Grommet Kit To protect wire from sharp edge (going through metal hole) 1 View
12V LOADS
1 Maxxair 6200K Roof Fan Fan Installation 1 Amazon
2 LED Ceiling Lights (Dimmable) 3 Amazon
3 PWM Dimmer for LED Lights, 12V, Slider 1 Amazon
4 Blue Sea 12V Socket Electrical System Guide 4 Amazon
5 Shurflo Revolution Water Pump, 3 GPM 1 Amazon
6 ON/OFF Switch for Water Pump 1 Amazon
7 Webasto Air Top 2000 STC Gasoline Heater Webasto Installation 1 Amazon
8 Propex HS2000 Propane Heater Propex Installation 1 Dealers
9 Novakool R5810 Fridge, 12V only Fridge Guide 1 Campervan-HQ
10 Sirocco ii Gimbal Fan, 12V Sirocco ii Installation/Review 1 Amazon
11 Nature’s Head Composting Toilet Toilet Installation 1 Amazon
12 Propane Solenoid Shutoff Valve 1 Amazon
13 ON/OFF Switch for Propane Solenoid 1 Amazon
High-Power

Optimized for high-power devices (induction cooktop, microwave, etc.)

KEY FEATURE:

The inverter, shore power and transfer switch are combined into a single device (Victron Multiplus).

MORE FEATURES:
  • BATTERY BANK: 200Ah and up (two or more batteries)
  • SOLAR: None or up to 700W
  • ALTERNATOR: None or up to 60A
  • SHORE: up to 120A DC
  • AC IN: 30A (campground hookup) or 15A (normal house outlet, via adapter)
  • INVERTER: 2000W or 3000W
  • TRANSFER SWITCH: Yes (automatically bypass inverter when plugged into shore)
  • 120V AC Distribution Panel: Yes (each load is protected by an appropriate breaker)
CHOOSE THIS DIAGRAM IF:
  • Your build includes any high-power device: air conditioning, induction cooktop, electric water heater, electric space heater, etc.
  • You frequently plug into shore power (serviced campgrounds).
  • You simply prefer an inverter/charger (Victron) instead of a separate inverter & battery charger.
MAIN
# Item Description Qty View on Amazon
1 Class T Fuse, 400A Blue Sea (Catastrophic Fail Safe) 1 View
2 Class T Fuse Block Blue Sea (Holds the Class T Fuse) 1 View
3 System Switch Blue Sea (Main System Switch) 1 View
4 Bus Bar (600A, 4 studs) Blue Sea 2 View
5 Cover for Bus Bar (for 600A 4 studs) Protect the Bus Bar 2 View
6 40A Breaker/Switch, Surface Mount Between Fuse Block and Bus Bar 1 View
7 Fuse Block (12 circuits) Blue Sea (12V Distribution Panel) 1 View
8 Fuses Kit Assorted Fuses (2A 3A 5A 7.5A 10A 15A 20A 25A 30A 35A) 1 View
9 Battery Monitor Victron BMV-712 with BlueTooth 1 View
10 Cable, 4/0 AWG, 5 ft Red Between battery and Bus Bar 1 View
11 Cable, 4/0 AWG, 15 ft Black Between battery and Bus Bar + Ground 1 View
13 Lugs, 4/0 AWG Cable, 5/16″ Ring Connect to Bus Bar, Terminal Fuse Block and Battery (Pack of 2) 1 View
12 Lugs, 4/0 AWG Cable, 3/8″ Ring Connect to System Switch and Shunt (Pack of 10) 1 View
14 Cable, 8 AWG, 5 ft Black + 5 ft Red Between Bus Bar and Fuse Block 1 View
15 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring Connect to Fuse Block (Pack of 3) 1 View
16 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breaker (Pack of 3) 1 View
17 Heat Shrink Terminal Ring, 8 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 3) 1 View
BATTERY
1 LiFePO4 400 Ah Battle Born LiFePO4 100 Ah 12V 4 View
2 4/0 AWG Cable in 5/16″ lugs, 1 feet Red + 1 feet Black Spartan Power 3 View
SOLAR
1 350W Solar NewPowa 175W Mono Panel 2 View
2 Extension Cables, 8 AWG, 15 ft Red + 15 ft Black With MC4 Connectors 1 View
3 Double Cable Entry Gland For 8 AWG or 10 AWG Cable 1 View
4 40A Breaker/Switch, Surface Mount Between Panels and MPPT Charger 1 View
5 MPPT Solar Charger Victron 100|30 SmartSolar MPPT 1 View
6 40A Breaker/Switch, Surface Mount Between MPPT Charger & Battery 1 View
8 Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 3) 2 View
7 Heat Shrink Terminal Ring, 8 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 3) 1 View
ALTERNATOR
1 60A Battery-to-Battery Charger (B2B) Sterling Power BB1260 1 View
2 100A Breaker/Switch, Surface Mount Blue Sea 285-Series 2 View
3 Cable, 4 AWG, 15ft Red WindyNation 1 View
4 Cable, 4 AWG, 5 ft Black WindyNation 1 View
6 Lugs, 4 AWG Cable, 1/4″ Ring Connect to Breakers (Pack of 10) 1 View
5 Lugs, 4 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 2) 1 View
INVERTER/CHARGER
1 3000W Inverter/Charger Victron Multiplus 12|3000|120 1 View
2 Remote Control for Inverter Victron Digital Multi Control 200/200A GX 1 View
3 Class T Fuse, 400A Blue Sea (To protect inverter’s cable) 1 View
4 Class T Fuse Block Blue Sea (Holds the Class T Fuse) 1 View
5 Cable, 4/0 AWG, 5 ft Black + 5 ft Red Between Inverter/Charger & Bus Bars View
6 Lugs, 4/0 AWG Cable, 5/16″ Ring Connect to Inverter/Charger (Pack of 5) 1 View
7 Lugs, 4/0 AWG Cable, 3/8″ Ring Connect to Bus Bar (Pack of 5) 1 View
8 30A Shore Inlet Furrion 30A Marine Power Smart Inlet 1 View
9 30A AC Main Breaker Between Power Inlet and Inverter/Charger 1 View
11 10/3 AWG Triplex AC Marine Wire Between power inlet & inverter/charger 1 View
12 Lugs, 10 AWG Cable, #8 Connect to AC Main (Pack of 3) 1 View
13 Lugs, 10 AWG Cable, #10 Connect to AC Main (Pack of 3) 2 View
14 120V AC Distribution Panel (4 Positions*) Blue Sea Panel: AC Main + 4 Positions* 1 View
15 6/3 AWG Triplex AC Marine Wire Between inverter/charger & AC distribution panel 1 View
16 Lugs, 6 AWG Cable, #10 Connect to distribution panel (Pack of 10) 1 View
17 120V AC Wall Outlet GFCI, 20A 1 View
18 14/3 AWG Triplex AC Marine Wire To wire load that requires 15A or 10A breaker 1 View
19 Lugs, 14 AWG Cable, #8 Connect to distribution panel (Pack of 3) 1 View
20 Lugs, 14 AWG Cable, #10 Connect to distribution panel (Pack of 3) 1 View
OPTIONAL ITEMS
1 50A Breaker (Double-Pole) To upgrade 120V AC distribution panel to 50A instead of 30A View
2 20A Breaker For load that requires 20A breaker (e.g. A/C) View
3 10A Breaker For load that requires 10A breaker View
4 120V AC Distribution Panel (6 Positions*) *6 Positions panel is sometimes cheaper, check it! View
5 12/3 AWG Triplex AC Marine Wire To wire load that requires 20A breaker (e.g. A/C) View
6 Lugs, 12 AWG Cable, #8 Connect to AC Main (Pack of 3) 1 View
7 Lugs, 12 AWG Cable, #10 Connect to AC Main (Pack of 3) 1 View
HARDWARE
1 8 AWG Black/Red Duplex Cable (8/2), Ancor Marine Grade 100 feet 1 View
2 10 AWG Black/Red Duplex Cable (10/2), Ancor Marine Grade 100 feet 1 View
3 12 AWG Black/Red Duplex Cable (12/2), Ancor Marine Grade 100 feet 1 View
4 14 AWG Black/Red Duplex Cable (14/2), Ancor Marine Grade 100 feet 1 View
5 16 AWG Black/Red Duplex Cable (16/2), Ancor Marine Grade 100 feet 1 View
6 Heat Shrink Terminal Ring, 8 AWG Cable, #10 Ring To connect to Fuse Block (25 Pack) 1 View
7 Heat Shrink Terminal Ring, 10-12 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
8 Heat Shrink Terminal Ring, 14-16 AWG Cable, #8 Ring To connect to Fuse Block (25 Pack) 1 View
9 Heat Shrink Butt Connector, Ancor Marine To connect to Loads (75 Pack Kit) 1 View
10 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Female
To connect to certain loads (i.e. 12V Sockets) , to make “removable” connections (i.e. Fridge, LEDs) and to connect cable of different gauge together (i.e. LED Dimmer) (25 Pack)
1 View
11 Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Male 1 View
12 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Female 1 View
13 Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Male 1 View
14 Heat Shrink Disconnect, 18-22 AWG Cable, 1/4″ Tab, Male 1 View
15 3M Scotchlok Quick Splice with Gel (14 AWG stranded) We used that to parallel our LED lights (25 Pack) 1 View
16 Heat Shrink Tubing Kit (with adhesive) To protect lug after crimping 1 View
17 Split Loom Tubing, 3/8″ diameter 25 feet To protect wire bundles 1 View
18 Split Loom Tubing, 1/2″ diameter 25 feet To protect wire bundles 1 View
19 Split Loom Tubing, 3/4″ diameter 10 feet To protect wire bundles 1 View
20 Nylon Cable Clamps Kit To secure cable/split-loom to wood 1 View
21 Zip Tie Mount with Adhesive To secure cable/split-loom to metal 1 View
22 Nylon Zip Ties Kit To secure cable/split-loom 1 View
23 Rubber Grommet Kit To protect wire from sharp edge (going through metal hole) 1 View
12V LOADS
1 Maxxair 6200K Roof Fan Fan Installation 1 Amazon
2 LED Ceiling Lights (Dimmable) 3 Amazon
3 PWM Dimmer for LED Lights, 12V, Slider 1 Amazon
4 Blue Sea 12V Socket Electrical System Guide 4 Amazon
5 Shurflo Revolution Water Pump, 3 GPM 1 Amazon
6 ON/OFF Switch for Water Pump 1 Amazon
7 Webasto Air Top 2000 STC Gasoline Heater Webasto Installation 1 Amazon
8 Propex HS2000 Propane Heater Propex Installation 1 Dealers
9 Novakool R5810 Fridge, 12V only Fridge Guide 1 Campervan-HQ
10 Sirocco ii Gimbal Fan, 12V Sirocco ii Installation/Review 1 Amazon
11 Nature’s Head Composting Toilet Toilet Installation 1 Amazon
12 Propane Solenoid Shutoff Valve 1 Amazon
13 ON/OFF Switch for Propane Solenoid 1 Amazon

Don’t worry about making too much sense of this for now… The goal of this guide is to slowly build your knowledge until you fully understand this wiring diagram. So relax, grab a drink, and keep reading. 🙂


2. Electricity for Dummies


This is not an electrician degree we’re doing here, but there is a bare minimum you must be willing to learn 🙂 This is to prevent mistakes, to feel confident about your project, but also to ensure we all speak the same language. Don’t worry, we’ll only cover the basics here, let’s go!

After reading this section, you will be able to:

  • Understand the basic concepts and terminology related to electricity.

2.1. Ohm’s Law


Electricity is the movement (flow) of electrons through a conductor. The electrons always have to overcome a certain resistance when flowing through a conductor:

Ohms-law-Doodle
Potential (Voltage)

Volt (V)

Difference in charge between two points. It is the force that enables current to flow through a conductor.

Resistance

Ohm (Ω)

Opposition to current flow.

Current

Amp (A)

Flow of electrons through a conductor.

Thanks to Ohm’s law, we can calculate how much current flows through a conductor:

Ohm’s Law

Current (A) = Potential (V) / Resistance (Ω)

Ohm’s law is kind of a big deal: it lays the foundation for most calculations in electricity. And as far as we’re concerned, it allows us determine wire/cable size (cross section diameter) and to select the appropriate overcurrent device size (fuse/breaker), but we’ll get to that later.

2.2. Analogy With Water


Electricity can be a bit abstract, so we like to think of it as water (of course that’s not technically accurate, but it’s good enough to make sense of all of this!):

ELECTRICITYWATER
CapacityTotal amount of energy available
(Ah)
Total amount of water available
(gal)
PotentialDifference in charge between positive and negative
(V)
Difference in height between top and bottom
(ft)
FlowRate at which energy is substracted from the battery
(A)
Rate at which water is substracted from the tank
(gpm)
Capacity

AMP HOUR (A⋅h)

Amount of energy stored in a battery.

The unit of capacity is Ah (1 amp x 1 hour), not A/h (amp per hour)! It is the amount of energy resulting by allowing 1 amp of current for 1 hour. For example, a battery that has 100Ah capacity can deliver any of this:

  • 100A current for 1 hour.
  • 50A current for 2 hours.
  • 20A current for 5 hours.
  • And so on!
Example:
ELECTRICITYWATER
Initial Capacity200 Ah20 gal
Flow4 A2 gpm
Duration8 h5 min
Consumption
(Flow x Duration)
32 Ah
(4A x 8h)
10 gal
(2gpm x 5min)
Remaining capacity
(Capacity – Consumption)
168 Ah
(200Ah – 32Ah)
10 gal
(20gal – 10gal)

2.3. POWER


Power (watts, W) is the rate at which the electrical energy is absorbed (or generated). And most of the time, the consumption of a load is represented in watts (W). However, sometimes, it is defined in amps (A). Both are technically correct and can be linked by the following equation:

Power (W) = Current (A) x Voltage (V)

For example, for a given system where voltage remains the same (12V), it would be accurate to say that a fridge draw 4.4 amps or 52.8 watts. Both are equivalent:

52.8W = 4.4A x 12V

Similarly, for a 12V system, it would be accurate to say that the capacity of a battery is 100 Amp-hour (Ah) or 1200 Watt-hour (Wh):

1200Wh = 100Ah x 12V

To avoid any confusion and for consistency’s sake, we will use the following units throughout this guide:

  • Load consumption (DC): Amps (A).
  • Load consumption (AC): Watts (W).
  • Battery capacity: Amp-hour (Ah).

Speaking of DC and AC. Electricity as we know it, provided in our house, is Alterning Current (AC), also known in North America as 110V/120V. The battery used in a van delivers Direct Current (DC), and is sold as 6V, 12V, 24V, or even 48V batteries. It is possible to use our home appliances (120V) in a van only through a power inverter.

A power inverter plays two roles:

  1. Convert direct current (DC) from the battery bank to alternating current (AC).
  2. Step up voltage from 12V to 120V.

Also, it is worth mentioning that the power (W) of a load is independent of voltage change. For example, a 1,500W (120V) hair dryer is still consuming 1,500W on the 12V side. However, the current (A) increases dramatically on the 12V side (125A) compared to the 120V side (12.5A):

1500W = 12.5A x 120V = 125A x 12V

Power-vs-Current-Clarification-2
Current (A) = Power (W) / Voltage (V)

Why should you care? Well, current is critical when sizing the wires. Indeed, a wire carrying 125A must be much thicker than a wire carrying 12.5A. Think of the water analogy: we need a much larger hose to allow a flow of 125 gpm of water, compared to 12.5 gpm… More on this in the Wires & Cables section.


3. Battery Bank


Because energy from the charge sources is not available at all times, a battery bank is mandatory in every van electrical system. The role of the battery bank is to accumulate energy from the charge sources, store it, then release it to the loads when needed.

After reading this section, you will be able to:

  • Understand the benefits and drawbacks of different battery chemistry types, in order to choose the type that better suits your needs.
  • Learn the terminology and understand data sheets, in order to adequately select a battery model.
  • Understand how to operate and select a battery (charge/discharge profile, temperature), in order to maximize its life expectancy.
  • Understand how to combine batteries (parallel/series), in order to get the desired battery bank characteristics.

3.1. Battery Types


A battery stores energy under chemical form, then converts it to electrical energy when needed. There are many battery types (chemistry) available, and each have their pros/cons:

Flooded Lead-Acid
Pros
  • Cheapest of all types.
Cons
  • High maintenance (needs to be filled periodically with water and kept in a vented compartment).
gEL-cELL
Pros
  • Similar to Flooded lead-acid, but the gel wont spill as easily.
Cons
  • See Flooded lead-acid.
  • Must be charged at low rate.
AGM
Pros
  • Low Maintenance (no need to refill with water, no need to be vented).
  • Performs well under most temperature range.
  • Can be charged/discharged at higher rate than Flooded Lead-Acid.
Cons
  • Much heavier than Lithium.
  • Shorter life span than Lithium.
Lithium (lifepo4)
Pros
  • Light weight.
  • No need to be vented.
  • Can be discharged deeper without affecting battery life (meaning a 100Ah Lithium delivers almost twice the energy of a 100Ah AGM or Flooded).
  • Can be charged/discharged at higher rate than AGM.
  • Low self-discharge (2-3% per month).
  • Much more life cycle than any other type (not so expensive in the long run).
Cons
  • Higher upfront cost.
  • More sensitive than other types, they require a BMS. See below for more info.

Unless you’re on a very tight budget, we don’t really recommend flooded lead-acid or gell-cell (because of the maintenance/venting).

We will therefore put the emphasis on AGM and Lithium for the rest of this guide. In this day and age, Lithium batteries are far more common than AGM. But that doesn’t mean AGM’s are obsolete… Let’s dig a bit deeper!

Lithium/AGM Comparison

AGM batteries should ideally not be discharged below 50%, and for that reason we compare a 100Ah Lithium battery to a 200Ah AGM battery.

LITHIUMAGM
Capacity100Ah200Ah
Usable Capacity1100Ah100Ah
Weight31 lbs130 lbs
Dimensions (L x W x H)12.76 x 6.86 x 8.95 in20.6 x 9.4 x 8.8 in
Discharge Temperature Range-4 to 135F (-20 to 57°C)-4 to 135F (-20 to 57°C)2
Charge Temperature Range25 to 135F (-4 to 57°C)-4 to 135F (-20 to 57°C)2
Charge/Discharge ProfileSimpleSensitive
Self-Discharge Rate (monthly)3%30%
Requires BMS?YesNo
Total Life Cycles30001200 3
Cost (upfront)$875$400
Cost (per cycle for 3000 cycles)$0.29$0.40

——————
1 Assuming 50% DOD (Depth Of Discharge) for AGM.
2 If SOC (State Of Charge) is above 60%.
3 Total life cycles vary with manufacturers. 1,200 cycles is considered a general rule of thumb.
* In the table above Lithium=BattleBorn, AGM=Renogy.

AGM vs Lithium Takeaways
  • Usable Capacity: Discharging AGM batteries below 50% greatly reduces its lifecycle; it is economically advantageous not to discharge below that point. That’s why we compare a 200Ah AGM battery to a 100Ah Lithium battery.
  • Weight: Lithium batteries allow weight saving up to about 75%, that’s huge! That means less weight to carry around in the van (gas saving) and it reduces the risk in case of an accident.
  • Dimensions: Space optimization is the name of the game in a van conversion, so each opportunity is considered. Lithium takes the win here!
  • Charge Temperature Range: Lithium batteries don’t charge too well below freezing (see section below), but manufacturers now produce self-heated batteries which mitigate this weakness.
  • Charge/Discharge Profile: To prevent permanent damage (capacity loss), AGM requires specific discharge profile (not below 50%) but also specific charge profile (bulk, absorption, float). Lithium are not as sensitive, they’re a little bit more “set-and-forget”.
  • BMS: Lithium batteries are more sensitive to current/voltage/temperature, thus they require an BMS (Battery Management System). The BMS won’t allow charge/discharge when going out of range (temperature too high/low, too much current, etc.). Most Lithium batteries have an integrated BMS these days, so it’s “transparent” for the user.
  • Total Life Cycles: Capacity reduces as batteries are cycled. For Lithium, approximately 80% of capacity remains after about 3000 cycles, while it’s only about 1200 cycles for AGM. In other words, a Lithium battery should last much longer than AGM.
  • Cost: Lithium batteries upfront cost is higher, but in the long they’re actually cheaper to own than AGM (because of their total life cycles).
AGM vs Lithium: Our Experience

Back in 2016, we initially went with an AGM battery (230Ah capacity), and spent our first two years of full time vanlife with it. We then upgraded to Battle Born’s Lithium (2 x 100Ah capacity). While upgrading resulted in more usable capacity, the major difference is that we pretty much stopped monitoring and worrying about the battery getting a complete charge cycle daily. That means less effort to park in the sun (solar) or drive the extra mile to get more charge from the alternator.

AGM-vs-Lithium-Battery-in-Van

Decision

In our humble opinion, Lithium batteries are definitely the way to go these days. When we upgraded from AGM to Lithium, we basically stopped to constantly monitor the SOC (because going 50% didn’t matter anymore) and stopped monitoring the charge profile (because ideally AGM require a complete absorption/float at each cycle). Lithium batteries are more “set-and-forget” than AGM.

Like most people out there, we went for the tried-and-true Battle Born Batteries. Outstanding product, warranty, and customer service. We’ve been using them trouble-free for years:

Battle Born Batteries
Battle-Born-Batteries-100Ah-12V-Lithium-LiFePO4
BB10012 (100Ah, 12V). A classic that sets the bar still to this day! Buy on Amazon.
Battle-Born-Batteries-GC3-270Ah-12V-Lithium-LiFePO4
GC3 (270Ah, 12V). New form factor and capacity to simplify mounting. Less cables & connections. Buy on Amazon.
Battle-Born-Batteries-BB10012H-Heated-100Ah-12V-Lithium-LiFePO4
BB10012H (100Ah, 12v). Self-heating to allow charging in sub-freezing temps. Battle Born.

3.2. Specifications


Not all batteries are made equal! For example, a cheap or generic battery may not deliver as much current, causing intermittent performance problems. To prevent getting caught, always check the data sheet; it should be available on the product page. No data sheet? Consider a different brand!

Here is an example of Battle Born data/specifications sheet (click the images to enlarge):

Battle-Born-BB10012-Data-Sheet-1
Battle-Born-BB10012-Data-Sheet-2

Information is clearly shown, it’s straight-to-the-point, there is no marketing sales pitch… well done!

Terminology:

  • Self-Discharge: This is the % of charge that is lost during storage. Lithium batteries have very low self-discharge rate, and can therefore be stored for long period without having to periodically recharging them.
  • Cycles (or Life Cycle): Number of cycles before the battery’s end of life.
  • Maximum Discharge Current: That’s the current the battery is able to deliver continuously. Power inverters draw HUGE amount of current, so make sure to size your battery bank so that its discharge current is greater than the inverter’s draw! (as a general rule of thumb, 1000W inverter = 100Ah battery bank, 2000W inverter = 200Ah battery bank, etc.)
  • Recommended Charge Current: Charging a battery too fast decreases its lifecycle, so choose a battery charger that charges within that range! (0.5c means 0.5 x battery bank capacity; e.g. for a battery bank comprised of 2 x 100Ah Battle Born Batteries connected in parallel, “0.5c” = 0.5 x 200Ah = 100A)
  • Maximum Charge Current: Never exceed that value.
  • Voltage (absorption, float, equalization) and Time: That’s called the “charging profile” and we explain it later 🙂
  • Temperatures: Lithium/AGM have different specifications. Different brands of the same chemistry have different range as well.

3.3. Maximizing life cycle


Batteries don’t last forever. If you’re going for the long run, there’s a pretty high chance you will have to replace your battery bank in your van at some point. Life expectancy of batteries is highly influenced by the conditions of operation; that means YOU can take precautions to increase life expectancy and protect your investment. Let’s see how!

But first, some terminology:

Cycle

A cycle is completed when you’ve used (discharge and then recharged) an amount that equals 100% of the battery’s capacity. This doesn’t have to happen in a single charge! For example, if you use 70% of the battery’s capacity one day, recharge it fully, then use 30% the other day, you’ve completed one cycle (over two days).

Life Cycle

As the number of cycles increases, a battery looses it’s ability to return to its initial capacity. The life cycle is the number of cycles that the battery can complete before loosing too much capacity. As a rule of thumb, the end of life cycle is reached when it cannot hold more than 75%-80% of its originial capacity.

State Of Charge (SOC)

The state of charge (SOC) is defined as “how fully charged” the battery is.

100% SOC: fully charged.

25% SOC: 1/4 capacity left.

0% SOC: empty.

The life cycle varies greatly with battery chemistry (as seen previously). But it’s also influenced by the charge profile, discharge profile, temperature, and long term storage. Keep reading!

3.4. Charge Profile


An adequate charge goes through multiple stages; each stage has specific current/voltage parameters. The combination of these stages is called the charge profile. Different battery chemistry (AGM, Lithium, etc.) and different brands (Battle Born, Trojan, Renogy, etc.) require different charge profiles. 

Typical Charge Profile:

(Consult the data sheet of your brand/model to find its recommended charge profile!)

AGM
Stage 1: Bulk
  • SOC: Between 0% and 85%.
  • Current: BIG! As much as the charger can “push” into the battery! (battery’s recommended charge current)
  • Voltage: Increases with time.

During that stage, the battery doesn’t offer much resistance to charging. It’s easy for the charger to push energy into the battery, so a low voltage results in a large current; in other words, most of the energy is transferred during that stage. As the battery charges, it offers more and more resistance; it’s much more difficult for the charger to push energy into the battery. If only bulk stage is used, the battery cannot be fully charged…

STAGE 2: ABSORPTION
  • SOC: Between 85% and 100% of the charge.
  • Current: LOW. Decreases with time.
  • Voltage: Fixed (around 14.7V)

Near 85%, the battery becomes much more resistant to charging… to keep pushing energy into the battery, the charger raises the voltage. You can clearly observe that on your battery monitor (high voltage, low charging current). It’s kind of like switching to first gear on your car: it’s more powerful, but slower. During that stage, the high voltage results in gassing inside the battery; this gas stirs the electrolytes and helps dissolve the small sulfate crystals. That’s why a proper absorption stage is so important! It prevents hard deposits (sulfuration) and, therefore, prevents loss of total capacity memory.

STAGE 3: FLOAT
  • SOC: Once the battery is fully charged.
  • Current: VERY LOW. (typically lower than 1A)
  • Voltage: Fixed (around 13.8V)

The float stage prevents self-discharge and can be maintained indefinitely.

Lithium
STAGE 1: BULK
  • Current: BIG! As much as the charger can “push” into the battery! (battery’s recommended charge current)
  • Voltage: Increases with time.

The bulk stage is terminated when the absorption voltage is reached (around 14.4V).

STAGE 2: ABSORPTION
  • Current: LOW. Decreases with time.
  • Voltage: Fixed (around 14.4V)

The absorption stage is terminated when current decreases below approximately 5% of the battery capacity (approx. 5A for a 100Ah battery).

STAGE 3: FLOAT
  • Floating a Lithium battery is unnecessary, but it won’t hurt it.
  • Voltage: Fixed (around 13.6V)
Good to know:

Lithium batteries don’t suffer from sulfuration, so charging with the wrong charge profile is not as bad as with lead-acid batteries. Charging with the wrong profile could prevent reaching 100% charge, but that won’t hurt the battery in the long term. Good to know: Most Lithium batteries are OK to charge with an AGM profile!

The SOC reached during a charge cycle, and completing all stages is quite important for the life cycle of lead-acid batteries (AGM). On the other hand, Lithium batteries are not as impacted by the SOC reached during a charge cycle.

Takeaway points to maximize life cycle during charge:
AGM
  • Charge rate: Typically 20% of capacity (0.2c).
  • Charge profile: Completing all stages is critical to the life cycle. It is therefore important to design a system that allows a complete charge cycle frequently (e.g. by having solar + alternator chargers, and sizing them adequately).
Lithium
  • Charge rate: Typically 50% of capacity (0.5c).
  • Charge profile: Completing all stages is not that critical; no need to monitor frequently and go crazy with this.

3.5. Discharge Profile


How a battery is discharged also affects its life cycle. The depth of discharge and discharge rate are of our interests here:

Depth Of Discharge (DOD)

The depth of discharge (DOD) is defined as “how deep” the battery is discharged (it’s the opposite of SOC…):

25% DOD: 1/4 of total energy available was used (75% SOC).

75% SOC: 3/4 of total energy available was used (25% SOC).

100% DOD: Fully discharged (0% SOC).

The DOD is quite important for lead-acid batteries (e.g. AGM). Indeed, discharging an AGM battery below 50% DOD greatly reduces its life cycle and is not economically advantageous:

On the other hand, Lithium batteries are not as impacted by the DOD. That’s why we generally consider that nearly 100% of capacity is usable on a Lithum battery.

Discharge Rate

The discharge rate is defined as how fast a battery bank is discharged (current).

For lead-acid batteries (e.g. AGM), the discharge rate affects not only the life cycle, but also the available capacity. As discharge rate increases, the battery’s available capacity decreases (for a given cycle, this is not permanent). This is called Peukert’s law, and that explains why lead-acid batteries have several ratings for their capacity.

For example, let’s take the capacity rating of a Roll’s 12V 230Ah AGM battery:

Hour RateCapacityCurrent
100 Hour Rate230Ah2.3A
20 Hour Rate210Ah21A
10 Hour Rate189Ah18.9A
5 Hour Rate172Ah34.4A
  • If this battery is completely discharged in 100 hours (at a slow rate of 2.3A), it can deliver 230Ah capacity.
  • If discharged in 20 hours (at a faster rate of 21A), it can deliver 210Ah capacity.
  • And so on…

On the other hand, Lithium batteries are not subject to Peukert’s law! The discharge rate don’t affect the usable capacity.

Takeaway points to maximize life cycle during discharge:
Lithium
  • DOD: No significant impact.
  • Discharge rate: No significant impact.
AGM
  • DOD: Life cycle is impacted at DOD over 50%.
  • Discharge rate: Life cycle and usable capacity is impacted as discharge rate increases.

3.6. Effect of temperature


Generally, batteries perform better near room temperature. For example, take electric cars: their range in a cold climate is greatly reduced during winter! That’s another reason why we installed our battery bank inside the van; exterior temperature has less impact on our battery that way.

Charging A Frozen Battery

Lithium (LiFePO4)

We often hear that a lithium battery cannot be charged below 32F (0°C); In fact, Lithium batteries can be charged below 32F/0°C, but at a slower rate. Check your battery specification sheet!

Take a look at Trojan Trillium LiFePO4 battery for example:

Trojan-Trillium-LiFePO4-Charge-Temperature

Good to know:

  • The built-in BMS in high-quality batteries will take care of cutting-off the current if temperature gets too low.
  • Some Lithium batteries are self-heated to allow lower temperature operation.
Lead-Acid (Flooded, Gel, AGM)

First of all, unlike water, a battery will not freeze at 32F (0°C). The freezing temperature of the battery depends on the state of charge. As the state of charge in a battery decreases, the electrolytes become more like water, and the freezing temperature increases.  It is very important to make sure your battery stays fully charged in extreme cold weather. If a battery freezes, it can damage the plates and container leading to a potential explosion. A frozen battery must NOT be charged!

As a guideline, this is extracted from Rolls Battery User Manual:

Specific Gravity (SG)State of Charge approx (%)Freezing Temperature
1.280100-69°C (-92F)
1.26592-57.4°C (-72.3F)
1.25085-52.2°C (-62F)
1.20060-26.7°C (-16F)
1.15040-15°C (5F)
1.10020-7°C (19F)

Charging a battery at high temperature

Charging a battery at high temperature generally affects its cycle life (lifespan). For example, here is the Trojan Trillium Lithium Cycle Life VS Temperature:

Trojan-Trillium-LiFePO4-Charge-Temperature-vs-lifecycle

3.7. Long Term Storage

Not planning on using your van for a while? Here are the storage parameters we recommend to maximime a battery’s life cycle:

SOC
  • Lithium: 50-70%. No need to recharge periodically (low self-discharge!)
  • AGM: 100%. Recharge periodically to maintain 100%.
Temperature
  • Lithium and AGM:
    • Ideal: 60F (15°C)
    • Recommended: 32F to 86F (0°C to 30°C)
    • Acceptable (may affect life cycle): -4F to 140F (-20°C to 60°C)

Depending on the climate you live in, batteries may be removed from the van and stored inside. We personally leave them in our van, with the following configuration:

Long Term Storage Mode
Lithium:
Wiring-Diagram-Long-Term-Storage-Lithium-Battery
The battery bank is disconnected from all the loads and charge sources.
AGM:
Wiring-Diagram-Long-Term-Storage-AGM-Battery
Solar is still connected to keep the AGM battery full. Periodically charging with shore would work too!

Recap (of Section 3.3.): Maximizing Life CYcle


Now that we better understand the factors that affect the life cycle of a battery, let’s do a quick summary of how life cycle can be maximized:

LITHIUMAGM
Life Expectancy3,000 cycles1,200 cycles
Charge Rate0.5c0.2c
Charge Profile ImportanceMedium. Aim for 100% recharge, but it’s not critical.High. Ideally each charge cycle should complete bulk/absorption/float.
Discharge Rate1cHigher discharge rate does not arm, but at the detriment of usable capacity (Peukert’s law)
Depth Of Discharge~90%50%
Charge Temperature25F to 135F (-4°C to 57°C)-4F to 135F (-20°C to 57°C) [if SOC is kept above 60% when temp < 32F (0°C)]
Discharge Temperature-4F to 135F (-20°C to 57°C)-4F to 135F (-20°C to 57°C)
Storage SOC50% to 70%. 100%. Recharge periodically.
Storage TemperatureIdeal: 60F (15°C).
Recommended: 32F to 86F (0°C to 30°C).
<- Same as Lithium.

3.8. Combining Batteries


Batteries can be connected together in parallel or in series:

Parallel
To increase total capacity
  • Capacity (Ah): Adds up.
  • Voltage (V): Same.
  • Charge & Discharge Rate (A): Adds up.

For example, adding two batteries of 12V/100Ah (50A charge rate / 100A discharge rate) in parallel results in a battery bank of 12V/200Ah (100A charge rate / 200A discharge rate).

parallel-battery-connection
Series
To increase voltage
  • Capacity (Ah): Same.
  • Voltage (V): Adds up.
  • Charge & Discharge Rate (A): Same.

For example, adding two batteries of 6V/200Ah in series results in a battery bank of 12V/200Ah.

series-battery-connection

In both cases, follow these recommendations:

  • Cables: Always use identical cables (length/diameter) so they offer the same resistance, ensuring all batteries work equally together.
  • Mixing batteries: Do not mix batteries of different brand/models. Do not mix batteries of different age if using lead acid (AGM, gel, etc.). It is acceptable to mix batteries of different age (no more than two years old) if using Lithium (see Battle Born FAQ).

3.9. 12V vs 24V Battery Bank


Lurking on the online discussion groups, we noticed more and more people consider building electrical system that operates on 24V battery bank instead of the traditional 12V battery bank. Here’s our take on it.

24V Battery Bank
Benefits
  • Allow to use smaller wire gauge.
    • Smaller wires are cheaper to buy, so it’s a cost saving opportunity.
    • On 12V, inverters over 3000W require cables greater than 4/0 AWG, so going 24V is definitely an advantage in that case.
  • Allow to use smaller solar charge controller for the same power input (W).
  • Slightly less energy loss when converting 24V DC to 120V AC.
Drawbacks
  • Smaller wires are harder to crimp and not as resistant.
  • 24V loads (fan, lights, water pump, inverter, etc.) are not as common. Sure, some of these devices are available for 24V, but an RV shop is less likely to have them in stock in case of an emergency.
  • You will need a 24V-To-12V converter, and to deal with a system that has 12V, 24V, and 120V. Make sure to identify everything properly!

In a few words, 24V electrical system starts to make more sense for larger rigs (such as RV) where several power-hungry appliances are used and a larger system is required. If you’re contemplating going for over 600Ah Lithium battery bank, 1450W of solar and having an inverter of over 3000W, then yeah you’re in 24V territory.

Every decision is a compromise between benefits and drawbacks, and personally our experience taught us that we’d rather priorise simplicity and parts availability over saving a few bucks (on wires). Here in North America, 12V is the most common standard and sticking with standards is generally a good idea. For example, our water pump failed while living full time in our van, but we were able to find a local RV shop that had our model in stock; a few hours later and our water system was back in operation. It’s sounds like a small anecdote, but the incertitude of a breakdown is always super stressful in the moment.

Getting feedback from experienced people is always a good idea. A quick search in our Facebook Group and we found a few similar comments:

24V System Feedback Comment on Facebook

In the end the decision is yours, and if you choose to go with 24V it’s totally fine, as long as you are aware of the pros and cons and make a clear distinction between the 12V and 24V side of your system 🙂


4. Charge Sources


Now that we understand the importance of charging a battery with an adequate charge profile, let’s see which charge sources are available!

After reading this section, you will be able to:

  • Understand how an external power source can be converted to a proper charge profile.
  • Identify which charge sources (solar/alternator/shore) applies to your needs.

4.1. Creating a proper charge profile


External power sources (e.g. solar panels, alternator, 120V outlet, etc.) don’t provide an adequate charge profile from the get go; the voltage and current are “random” and not suited to charge a battery. To make an external power source usable, a device (typically called a “charger” or a “controller”) is installed between the charge source and the battery. The role of the charger is to take the “random” voltage and current, and to convert it to a charge profile (voltage/current) suitable for a specific battery type:

External-Power-Source-Convert-Charge-Profile

4.2. Solar Power


Harvesting power from the sun feels a bit like cheating to us; this is the exciting part of the electrical system!

Solar panels catch energy from the sun and convert it into electricity (about 10-20%) and heat (about 80-90%). The % of the energy converted to electricity is called the efficiency of the solar panel (module). The voltage and current coming out of the solar panels are not ideal to charge a battery, and therefore a solar charge controller convert it to an adequate charging profile:

Solar-Power-Camper-Van

4.2.1. Rigid vs Flexible Solar Panels

Both rigid and flexible solar panels have their pros and cons, and which one’s best depends on your needs and priorities. Here are the key characteristics of both:

RIGIDFLEXIBLE
Efficiency15-20%7-15% (more surface required for same output as rigid)
DurabilityMaintains its efficiency longer.Looses efficiency faster over time.
StrengthA sturdy frame and tempered glass prevent damages to the panel.Prone to scratches and cracks.
WeightAbout 3x heavier than flexible.About 1/3 lighter than rigid.
ThicknessThicker, less aerodynamic.Lower profile = gas saving.
InstallationLimited to flat surfaces.Adapt to curved surfaces and various configurations.
Life Span25 years5 years
CostCheaper upfront and in the long run.Higher upfront and in the long run.
Solar Panels Installation
Rigid solar panels on our 2016 Ford Transit
Flexible-Solar-Panels-Installed-on-Ford-Transit
Flexible solar panels (credit: @humphreywhaleofavan)

4.2.2. Monocrystalline vs Polycrystalline Solar Panels

Most of the solar panels on the market can fit into two categories: monocrystalline or polycrystalline. The key takeaways are pretty straightforward:

MONOCRYSTALLINEPOLYCRYSTALLINE
Efficiency17-22%15-17%
Temperature DegradationEfficiency less affected by temperatureLoss of efficiency as temperature rises
AestheticsUniform black-ish (more attractive for most)Speckeld blue (less attractive for most)
CostHigherLower

That being said, the quality of the solar panel is more important than the type of the panel! So we’d rather recommend a good polycrystalline panel than a cheap monocrystalline…

monocrystalline-vs-polycrystalline-solar-panels
Monocrystalline vs Polycrystalline (source: Clean Energy Ideas)

4.2.3. Series vs Parallel

Solar panels can be combined in parallel or in series, with the following characteristics:

SERIESPARALLEL
VoltageAddedSame
CurrentSameAdded
Voltage DropMinimize voltage drop (allow to use smaller cables).Increase voltage drop (use thicker cables to compensate).
Partial ShadingHigher output degradation.Less impacted by partial shading.
InstallationEasier (no adapter required). MPPT solar charger only.*Adapter required (See on Amazon). MPPT or PWM solar charger.*
PerformanceMore efficient early/late during the day and at high temperature.More efficient in partial shading situations.

* See MPPT vs PWM section below.

Series
Solar-Panels-Series-Connection
Solar panels in series. No adapter required.

Solar panels in series results in a high voltage, low amperage array. Ideal for long cable runs and MPPT solar charger. Panels depend on each others, so partial shading could take down the whole array; not recommended when permanent partial shading cannot be avoided (e.g. roof accessories).

Parallel
Solar-Panels-Parallel-Connection
Solar panels in parallel. Adapter required:
MC4-Parallel-Adapters-Solar-Panels
Parallel MC4 Adapters (See on Amazon)

Solar panels in parallel results in a low voltage, high amperage array. Mandatory for PWM solar charger. Panels operates independently from each others, so partial shading output deterioration is mitigated.

4.2.4. Partial shading

Solar panels are made of multiple solar cells all connected together in series; blocking one of the cells totally kills the output of the solar panel. Think of the old Christmas tree lights: if one of the bulbs blew, the entire thing would go off! Fortunately, most modern solar panels have built-in bypass diodes that helps mitigate partial shading. In such solar panels, cells are split in 2 or 3 groups; if one cell is blocked, only the group comprising the blocked cell is “killed”. Other groups bypass the killed group:

Solar-Partial-Shading-from-Roof-Fan-Blocked
0% output without bypass diode.
Solar-Partial-Shading-from-Roof-Fan-With-Bypass-Diode
50% output with bypass diode.

Solar panels connected in series can get the output of the entire array down to 0% because of partial shading! Back to the water analogy:

Shaded-Cell-as-Clog-in-Pipe
0% output with solar panels in series and no bypass diode! (photo credit: aurorasolar.com)

Connecting the solar panels in parallel is a bit like adding bypass diodes; each panel operates independently and total output is not completely blocked:

Partial-Shading-Solar-Array
Total output:
  • No Partial Shading: 513W
  • Partial Shading | Bypass Diode | Series: 257W
  • Partial Shading | Bypass Diode | Parallel: 400W

Partial shading conclusion: Try to install your panels so they are not located in the shade of other roof accessories (roof rack, fan, etc.). If this is inevitable, connect your panels in parallel.

And that explains our roof layout:

Cleaning the solar panels 2
Solar panels away from any permanent shade.

4.2.5. Orientation

A panel will deliver more current if oriented perpendicularly to the sun. On large commercial solar plants, the panels are mounted on a motor-driven device that optimizes the orientation of the panel automatically throughout the day. Obviously there is no such device for a van roof (until when?), but, with some out-of-the-box thinking you can build your own system:

vandmvanlife-solar-panels-tilt-system
900W of tilted solar panels! Credit: RayOutfitted.com

We reached out to Ray at Rayoutfitted and he claims his tilt system can increase solar input up to 50% in winter. Pretty good!

Adding a tilt kit will obviously add weight, raise the panel(s), and have a negative impact on fuel consumption. If we were to park for extended period of time at the same place, we might consider a tilt kit. With our lifestyle, we generally move a few times each day, so we personally don’t feel like it’s worth the hassle.

4.2.6. Installation

We personally went for a simple DIY installation (faroutride.com/solar-panels-installation) on our 2016 Transit, but upgraded to a FlatLine Van Co. roof rack on our 2021 Transit:

Flatline Van Co Roof Rack
  • Modular: you can shuffle the cross bars around to fit your custom roof layout (e.g. solar panels/roof fan/etc).
  • Low profile: a bit more stealth and aerodynamic than the tubular aluminum “overland-style” roof rack.
  • Easy installation: it’s attached to the van’s roof with the factory mount points (no-drill!), and because they are modular they ship flat packed in a box and they are easier to install (less bulky).
  • Easy to install gear and accessories: the cross bars are 80/20 aluminum extrusions, so you can get creative and attach pretty much anything in any possible way: solar panels, decking, awning (Fiamma F45S direct-mount, no drill), light bar, etc.
  • Vans: Transit, Sprinter, ProMaster.
Flatline-Van-Co-FVC-Roof-Rack-Low-Pro

For more info (features, specifications, installation, ordering, etc.):

4.2.7. Solar charge Controller

A solar charge controller is responsible of delivering an adequate charge profile to the battery bank. In other words, it regulates the voltage and current coming from the solar panels and going to the battery bank.

MPPT vs PWM solar charge controller

The two types of solar charge controller available are MPPT and PWM. In a nutshell, MPPT will ouput 10-20% more power than PWM depending on the conditions. For this reason, MPPT has become the most popular option despite its higher cost.

MPPT
(Maximum Power Point Tracking)

The high voltage coming from the panels is dropped to a lower voltage, and this voltage reduction is converted into higher current.

  • Efficiency: About 10-20% more efficient than PWM, especially in non-ideal conditions (cloudy, low temperatures, etc.).
  • Panels/Battery Voltage: Works best when panels voltage is much higher than battery (panels combined in series).
  • Cost: Higher.
  • Best for: Larger systems where getting the most out of the panels is a priority.
PWM
(Pulse Width Modulation)

The high voltage coming from the panels is dropped by quickly turning the charge controller ON and OFF (10,000 times per second). This method of lowering the voltage does NOT produce more current (as opposed to MPPT).

  • Efficiency: Not as efficient as MPPT.
  • Panels/Battery Voltage: Panels voltage must be near the battery voltage (panels combined in parallel).
  • Cost: Lower.
  • Best for: Smaller systems where low cost is a priority.
MPPT vs PWM: Our Experience

Back in 2016 we initially went with a PWM solar charge controller (Bogard Engineering), then upgraded to a MPPT charger (Victron). We immediately noticed the difference: more current was going into to battery despite the fact that we didn’t change our solar panel setup. We also noticed more power earlier during the day and in overcast weather. Nice!

How to select a solar charge controller

Most MPPT solar charge controllers are defined by the maximum open circuit voltage and the maximum charge current:

1. Select a solar charge controller that is rated for your battery bank voltage (12V, 24V, etc.).

2. Make sure the Maximum Open Circuit Voltage rating (Voc) of the solar charge controller is higher than the maximum open circuit voltage of the solar array:

  • Panels in series: Voc(array) = Voc (single panel) x Number of panels x T°factor
  • Panels in parallel: Voc (array) = Voc (single panel) x T°factor

A note on T°factor: Voc is typically rated for 77F (25°C) and as temperature decreases, Voc increases. Because we’re mobile and our home-on-wheels will most certainly face cold temperatures at some point, we use 1.2 as T°factor.

3. Make sure the Maximum Charge Current rating of the solar charge controller is higher than the maximum charge current of the solar array:

  • Maximum Charge Current = Max Power (array) / Battery Charge Voltage (14.7V or 29.4V)
Example:
Solar-Charge-Controller-Sizing-MPPT-Victron

In the example above:

  1. The solar charge controller is rated for a 12V battery bank.
  2. The solar charge controller maximum open circuit voltage rating is higher than the array (100V > 47.6V).
  3. The solar charge controller maximum charge current rating is higher than the maximum charge current of the array (30A > 21.8A).

This MPPT solar charge controller calculator should make things a bit easier:

MPPT SOLAR CHARGE CONTROLLER CALCULATOR

1. SINGLE PANEL SPECIFICATIONS:

(CHECK DATASHEET OR MANUFACTURER’S WEBSITE)

Solar Panel Top View
MAXIMUM POWER (Pmax): W
OPEN CIRCUIT VOLTAGE (Voc): V
SHORT CIRCUIT CURRENT (Isc): A

2. SOLAR ARRAY:

SERIES:
PARALLEL:
BATTERY BANK VOLTAGE: 12V
24V
1S 1P- Solar Panel Array Series Parallel
2S 1P- Solar Panel Array Series Parallel
3S 1P- Solar Panel Array Series Parallel
4S 1P- Solar Panel Array Series Parallel
5S 1P- Solar Panel Array Series Parallel
6S 1P- Solar Panel Array Series Parallel
1S 1P- Solar Panel Array Series Parallel
2S 2P- Solar Panel Array Series Parallel
3S 3P- Solar Panel Array Series Parallel
4S 4P- Solar Panel Array Series Parallel
5S 5P- Solar Panel Array Series Parallel
6S 6P- Solar Panel Array Series Parallel
1S 3P- Solar Panel Array Series Parallel
2S 3P- Solar Panel Array Series Parallel
3S 3P- Solar Panel Array Series Parallel
4S 3P- Solar Panel Array Series Parallel
5S 3P- Solar Panel Array Series Parallel
6S 3P- Solar Panel Array Series Parallel
1S 4P- Solar Panel Array Series Parallel
2S 4P- Solar Panel Array Series Parallel
3S 4P- Solar Panel Array Series Parallel
4S 4P- Solar Panel Array Series Parallel
5S 4P- Solar Panel Array Series Parallel
6S 4P- Solar Panel Array Series Parallel

TOTAL POWER:
0 W

OPEN CIRCUIT VOLTAGE:
0 V

MAX CHARGE CURRENT:
0 A

3. RECOMMENDED MPPT SOLAR CHARGE CONTROLLER:

* This calculator assumes a temperature correction factor of 1.2.

You'll find the open circuit voltage (Voc) and the maximum power on your solar panel's datasheet:

NewPowa Solar Panel 160W Data Sheet
source: Newpowa

4.3. Alternator


The role of the alternator is to convert mechanical energy (engine) into electrical energy. This electrical energy is delivered to all the vehicle’s electrical components (lights, radio, etc.) and to charge the starter battery as well. It’s possible to “steal” electrical energy from the alternator to charge the house battery. Similarly to solar power, we need a device to regulate the voltage/current coming from the alternator:

Alternator-Power-Camper-Van

4.3.1. Accessing alternator power

Modern vehicles equipped with smart alternators (and regenerative braking) have finicky BMS (Battery Management System) and connecting anywhere into the system might confuse the BMS into thinking that the power used to charge the house battery is a "leak". Therefore, it is recommended to follow manufacturer's recommendations.

How to tap into alternator power is specific to each van's brand/model/variants... We can't possibly show all the possibilities, especially knowing it keeps on changing over the years! To prevent duplicate information (and mistakes), all the information we gather will be centralized and shared in this page: faroutride.com/b2b-review.

We're pretty familiar with the Ford Transit, so here's how to access alternator power:

Ford Transit 2020 & up | Dual Batteries

Since 2020, the Transit with dual battery configuration comes with two CCP (Customer Connection Point) located on the driver seat pedestal (on the door side). The CCP2 is rated for up to 175A, so it’s an ideal connection point recommended per the BEMM. Below is a photo of how we're connected to CCP2 in our Transit; it's a work in progress at the time of writing these lines and we'll update with the final photo soon! The photo shows the CCP2 location as well as how we mounted the breaker to protect the branch circuit (more info about that in Fuses & Breakers section).

4.3.2. DC-DC CHarger

(Aka DC-to-DC, Battery-To-Battery, B2B)

A DC-DC charger is the way to go these days, as it provides many advantages over the traditional isolator/ACR:

  1. It’s a smart charger, meaning it provides a multi-stage charge adapted to the battery type (AGM, Lithium, etc.). That’s important because it'll keep your house battery healthy and maximize its life cycle.
  2. It acts as a current limiter to prevent overworking the alternator. An alternator is a mechanical device and using it over its intended capacity can affect life expectancy.
  3. Easier to install: no need to wire to the vehicle ignition.
  4. It’s install-and-forget: the DC-DC charger will automatically activate/deactivate when driving to keep the house battery topped up.
  5. Modern DC-DC chargers are programmed to handle smart alternators and their highly variable voltage, ensuring a continuous and uninterrupted charge.

There are a few good DC-DC charger options out there:

Victron Orion (30A)
Victron-Orion-12-12-30-Non-Isolated-DC-DC-Charger

- The ISOLATED Victron Orion has two separate negative port, for when the installation does not share a common negative path (e.g. fiberglass boat).
- The NON-ISOLATED version is suited for installations sharing common negative path, and that is actually our case (i.e., starter & house battery share common ground).

Sterling Power (60A)
Sterling-Power-BB1260-DC-DC-B2B-Charger

To select the correct DC-DC charger size, we have to:

  • Not exceed the house battery bank charge rate (typically 0.5c for Lithium, 0.2c for AGM, per Charge Profile section above).
  • Not exceed the alternator's available current (varies with van brand/variant).
  • Take the features into account (bi-directional charge, voltage sensing, vibration sensing, smart alternator compatibility, fan noise, etc.).

A full analysis (products/brands comparison, sizing, pros, cons, dimensions, output, features, etc.) is out of the scope of this page, but we do have a dedicated page about DC-DC chargers. Going through this page will help you make the right choice:

4.3.3. Isolator and Automatic Charging Relay (ACR)

Isolators and ACRs combine the starter battery and the house battery together during the charge (engine on) and disconnect them during the discharge (engine off). They do not regulate the voltage or current. They’re good at “bulk-charging” the house battery, but they’re not so good at finishing the charge properly because the house battery is not getting an adequate charge profile. They're definitely cheaper upfront, but on the other hand, they are not great for the life cycle of batteries, and they tend to overwork alternators. For these reasons, we highly recommend the DC-DC charger option.

4.4. Shore


Shore power is a fancy name that means getting power from the grid, such as a house's 120V outlet or a campground's 30A/50A hookup. It's an expression borrowed from the marine's world which means providing electrical power from the shore to a ship while it's docked.

Similar to solar and alternator power, shore power requires a device to regulate the voltage and current. But unlike solar and alternator power, the current must also be converted from alternative current (AC) to direct current (DC). Let's get into it!

Shore-Power-Camper-Van

4.4.1. Battery Charger/Converter

The role of a battery charger/converter is to convert 120V AC coming from the shore into 12V DC and provide a multi-stage charge profile adapted to the battery type (AGM, Lithium, etc.).

We personally went for a Samlex America battery charger/converter, because of the brand's reputation of using high-quality components into their products. And as it turns out, it's been working trouble-free since day 1.

Samlex America
Samlex-SEC-1230UL-30A-Battery-Charger-Converter

*Samlex literature don't mention compatibility with Lithium batteries, but both Battle Born Batteries and Samlex have confirmed this charger works well with Lithium when using the AGM charge profile. Indeed, the recommended charge profile of the Battle Born Batteries (14.2-14.6V absorption, 13.4-13.8V float) falls right into this charger's AGM profile (14.4V in absorption, 13.5V in float).

4.4.2. Inverter/Charger

An inverter/charger acts as a battery charger/converter and as a power inverter. The functions of an inverter/charger are:

  1. Charge the battery bank. It converts 120V AC coming from the shore into 12V DC and provide a multi-stage charge profile adapted to the battery type (AGM, Lithium, etc.).
  2. Power the 12V DC loads. In our wiring diagram, the current coming from the battery charger/converter can "bypass" the battery and go straight to the loads.
  3. Power the 120V AC loads. It converts 12V DC coming from the battery into 120V AC to power the 120V loads (see Power Inverter section).
  4. Transfer switch. Some inverter/chargers also feature a built-in transfer switch (see Transfer Switch below).

It combines a charger/converter and a power inverter into a single device, and somewhat simplifies the system. The drawback is that if a failure is to happen, more functionalities are lost simultaneously.

Victron's Multiplus inverter/charger packs a lot of features in a high-quality product, it's definitely a crowd's favorite. Going through all of this would be a bit much here, so we have a dedicated page that covers the features and configuration:

4.4.3. sizing shore power

To select the correct shore charger, we have to:

  • Not exceed the house battery bank charge rate (typically 0.5c for Lithium, 0.2c for AGM).
  • That being said, it's not necessary to go all the way up to 0.5c for Lithium. For example, a 200Ah Lithium battery bank can accept up to 100A charge, but it's OK to select a 50A charger if you don't mind the extra time it'll take to fully charge the batteries.

4.4.4. Automatic Transfer switch (ATS)

An automatic transfer switch (ATS) is a priority switch that allows only one input at a time (typically shore power or generator on big RV) in order to prevent backfeeding or overload. On RV's, the ATS normally prioritize the generator input:

Automatic-Transfer-Switch-ATS-Motorhome-Generator-Shore

On top of that, RV are typically wired so that the AC distribution panel can only be fed by one input at the time (priority given to shore/generator):

RV-Schematic-ATS-1

Let's hook up a battery charger in there, and things start to look a bit complex:

RV-Schematic-(ATS)-2

An inverter/charger combines the inverter and the battery charger and simplifies things a little:

RV-Schematic-(ATS)-3

At last, most vans have modest power needs compared to motorhomes, so a generator is typically not required:

RV-Schematic-(ATS)-4

That's better :)

4.4.5. Shore hookup types

Here in North America, there are 3 types of outlet/hookup you may encounter. The usual 120V outlet (15A), and the campground's 120V hookups (30A and 50A):

15 Amp
15-Amp-120V-Outlet

3 prongs: 120V positive ("hot"), negative ("neutral"), ground ("earth").

30 Amp
30-Amp-120V-Outlet

3 prongs: 120V positive ("hot"), negative ("neutral"), ground ("earth").

50 Amp
50-Amp-120V-Outlet

4 prongs: 2 x 120V positive ("hot"), negative ("neutral"), ground ("earth").

4.4.6. Shore power inlet

15 Amp
Shore-Power-Inlet-(15A)

This 15A shore power inlet does not require hardwiring, an easy solution for our Standard Wiring Diagram.

30 Amp
Shore-Power-Inlet-Furrion-30A

A 30A shore power inlet should be sufficient for most vans, ideal for our High Power Wiring Diagram. (Installation instructions PDF)

50 Amp
Shore-Power-Inlet-Furrion-50A

A 50A shore power inlet is typically seen on larger motorhome. (Installation instructions PDF)

4.4.7. Shore power Cord

Shore power cord design varies (15A, 30A, 50A), so make sure to select a power cord that matches with your system:

4.4.8. Pigtail Adapter (Dogbone)

A pigtail adapter (aka dogbone) allows to connect to a different power configuration. For example, for connecting your 15A charger to a 30A outlet. You can also connect your 30A shore power inlet to a 15A "regular" house outlet, but you will be limited to 15A because that's the maximum it's capable of delivering. To prevent tripping the breaker on the 15A side, you have to limit the power input on the Multiplus inverter/charger (procedure described in our Victron Multiplus Guide).

Pigtail Adapters
Pigtail-Adpater-Dog-Bone-RV

This listing contains all types of pigtail adapter:

Note that installing an AC Main Breaker after the shore power inlet is highly recommended, in order to protect yourself from current surge and reverse polarity. Such as the Blue Sea AC Main Breaker 30A or 50A, which can be enclosed in a surface mount box:

Wiring-Diagram-AC-Main-Breaker-Shore-Power-Inlet
Shore Power AC Main Breaker (High-Power Diagram)

4.5. Generator


One of our favorite things about being off-the-grid is to feel close to nature and enjoy the silence. Generators don't get much love around the Vanlife community, as they very effectively spoil the vibe and provide a frustrating experience for the others around. If you do have a generator, a good etiquette is to run it in the middle of the day to charge your batteries, then turn it off during the evening/night/morning.

Fortunately, vans have modest power needs and with proper planning generators are normally not needed. An exception to this would be air-conditioning, because A/C is by far the most power-hungry appliance you can run. Running A/C off-the-grid is possible though, but you'll have to invest a lot in the electrical system. We do have a full article about that:

In a stationary scenario (no help from alternator or shore charging), it's almost impossible to sustainably run an A/C for extended period. A massive battery bank will buy you more time, but solar alone can't fully recover the energy and top up the battery bank. In that case, a generator may be needed. For vans, a portable generator connected to the shore power inlet should suffice (in other words, the generator acts as the shore power source):

Generator-as-shore-power-van-life

You should know that your battery charger (or inverter/charger) is sensible to voltage fluctuation. If you plan on using a generator with a Multiplus, make sure to read this to learn how to choose a generator and how to program the Multiplus: Multiplus Generator FAQ.

Also, getting the Digital Multi Control Remote (more info in our dedicated Victron Multiplus page) to limit the Multiplus input current may be a good idea, to prevent overloading the generator.

A high-quality generator will provide a stable voltage, run quieter and will be more fuel efficient:

Honda EU1000i
Honda-EU1000i-Generator

For (very) small power needs (definitely not A/C).

Honda EU2200i
Honda-EU2200i-Generator

Probably the best choice for vans. Best compromise on size/power/price. Should be able to power a 120V air-conditioning (but not more) when paired with a Soft-Start.

Honda EU3200i
Honda-EU3200i-Generator

Honda's latest offering. More power, but bigger and at a higher cost.

EU1000iEU2200iEU3200i
Maximum Output (surge)1,000W2,200W3,200W
Continuous Output900W1,800W2,600W
AC Output @120V7.5A15A21.7A
Displacement49.4cc121cc130cc
Fuel Tank Capacity.55 gal.95 gal1.2 gal
Length17.8"20.0"22.5"
Width9.5"11.4"12.0"
Height14.9"16.7"17.8"

4.6. Wind


Using a wind turbine while driving is a proposition that resurfaces occasionally on online forums. We'll keep it short: the additional drag caused by the wind turbine will increase the gas consumption and overall, there's more energy lost than gained. Better invest in a DC-DC charger!

For a permanent camp, it could be considered. But wind turbines are big and bulky, not really suited for a nomadic lifestyle. Solar is much more convenient. Here is a more in-depth page on BattleBorn website: Can a wind turbine power my RV?

4.7. charge sources you actually need


We've seen several ways to obtain power from external sources: solar, alternator, shore, generator, and wind (🤨). That doesn't mean you need all of them! But there's a reason why most vans are equipped with solar, alternator, and shore power. More options mean flexibility, resilience and peace of mind. The upfront cost is higher, but it's an insurance your electrical system will work in every scenario: long stretch of driving, stormy days, rest days, etc. Definitely recommended for:

  • Full time Van Life.
  • 4 season vans.
  • All-electric vans (no propane, high power needs).
  • AGM battery banks (need frequent full charge).
  • Better resale value.
Our Experience

We realized that it's difficult to plan how Vanlife will unfold. You dream of sunny days or driving for hours into the unknown... but the reality can be quite different. Here are a few real-world anecdotes:

  • We spent over a week In Oaxaca (see our Mexico Vanlife Guide), and we were fortunate enough to find a campground with a roof above us to protect us from the sun (it was HOT!). We used public transport over there, so that van was stationary. Our only charge source was shore power.
  • We spent our first two winter chasing the snow (see our Winter Vanlife Guide). With short days and low angled sun, solar is pretty much useless in this scenario. So, alternator power was our main charge source.
  • Covid was a weird period to live in a van. At some point, travel was restricted here in Canada, so we parked in the mountain and took the opportunity to work on this website for a few days. Solar power was definitely our main charge source.
Le Petit T Park Oaxaca Campground (6)
Oaxaca, Mexico. Protected from the sun!
Vanlife-Camper-Winter--Ski-Snowboard-Snow-Dump
Terrace, BC. Getting ready for a deep day :)

These are just a few random examples to show that things don't always go as planned. Better be prepared!

All of that being said, it all depends on your own needs. For example, some people build van without solar because they know they will drive long stretches every day. Discarding a charge source can be a way to cut on costs, so evaluate your needs and build accordingly!


5. 12V DC Loads


After reading this section, you will be able to:

  • Understand why you should prioritize 12V loads (or, more broadly, loads with same voltage as battery bank) over 120V loads.
  • Identify typical 12V loads found in vans/RVs.

5.1. 12V DC loads are more efficient


Any voltage conversion comes with energy loss. The energy loss from converting 12V DC to 120V AC is typically around 10-15%. Whenever you can, choose loads with the same voltage as the battery bank to increase the efficiency of your electrical system.

You should know that many appliances are actually DC, even if we take it for granted that they are 120V AC. For example, most smartphones require an input of 5V DC. So, using a 120V outlet to charge a phone will result in a double-conversion (12V DC -> 120V AC -> 5V DC):

AC-DC-Double-Conversion-Voltage-Current

5.2. 12V DC loads in our van (and more)


Sirocco II Gimbal Fan
Sirocco Elite II Fan Close-up
12 Volt DC Socket
12V-Socket-Blue-Sea
Phone Charger
Anker-USB-C-Car-Charger-12V
LED Lights (Dimmable)
Recessed-Ceiling-Light-LED-Acegoo-12V
LED (With Built-In Switch)
-Ceiling-Light-LED-Built-In-Switch-Acegoo
Buy on Amazon
Reading Light
Acegoo-12V-LED-Reading-Light
Buy on Amazon
Novakool Fridge
Novakool-R5810-Fridge-Refrigerator-12V-24V
Propane Solenoid
Advanced-Fuel-Components-AFC-151R-Propane-12V-Solenoid
Air Heater (Gas)
Webasto-Air-Top-2000-STC-Air-Heater
Air Heater (Propane)
Propex-HS-2000-Propane-Heater

6. 120V AC Loads


After reading this section, you will be able to:

  • Understand the role of inverters and inverter/chargers.
  • Learn the difference between pure sine and modified sine inverters.

6.1. Power Inverter


A power inverter plays two roles:

  1. Convert direct current (DC) from the battery bank to alternating current (AC).
  2. Step up voltage from 12V to 120V.

Pure Sine vs Modified Sine Inverters

Electric current is defined as the flow of charge (movement) of electrons.

  • Direct current (DC) is an electric current that flow in one direction.
  • Alternating current (AC) is an electric current that reverses direction periodically.

In DC, voltage is constant, while in AC, it oscillates between its positive and negative peak. When plotted on a chart (Voltage over time), AC voltage takes the shape of a sine wave:

Power inverters can be found as modified sine wave inverter or pure sine wave inverter. The difference lies in the ability of the inverter to reproduce the shape of the AC:

Modified Sine Wave

In a modified sine wave, the voltage rises and falls abruptly, the phase angle also changes abruptly, and it sits at 0 Volts for some time before changing its polarity:

Modified Sine Inverter Wave
  • Any device that uses a control circuitry that senses the phase (for voltage/speed control) or instantaneous zero voltage crossing (for timing control) will not work properly: fridge, microwave, clock, power drill, dimmer, fan, etc.
  • Produces enhanced radio interference, higher heating effect in motors/microwaves, and produces overloading due to lowering of the impedance of low frequency filter capacitors/power factor improvement capacitors.
Pure Sine Wave

In a pure sine wave, the voltage rises and falls smoothly with a smoothly changing phase angle and also changes its polarity instantly when it crosses 0 Volts:

Pure Sine Wave Inverter
  • Inductive loads like microwaves and motors run faster, quieter, and cooler.
  • Reduces audible and electrical noise in fans, fluorescent lights, audio amplifiers, TV, fax, and answering machines.
  • Prevents crashes in computers, weird print outs, and glitches in monitors.

Pure sine inverters cost more, but as we now understand, they are definitely worth it.

Energy loss

Remember that there is an energy loss of around 10%-15% during the conversion from DC to AC, so it’s better to avoid the inverter when possible (e.g., by charging your phone from a USB outlet).

Power Rating

Inverters are normally rated for the power they can continuously deliver on the 120V AC side. But remember that because there is an efficiency loss (around 15%), more power is drawn on the 12V DC side (battery):

Power-Inverter-Efficiency
High Current!

Remember that inverters draw a HUUUUGE amount of current (e.g. a 3000W inverter draws over 300 amps!) and are the most “dangerous” component of your electrical system. Make sure that your connections are p-e-r-f-e-c-t (and won’t loosen with time/vibration). In doubt, ask a professional to check your installation.

We had really good luck with our Samlex pure sine wave inverter (and our Samlex charger as well!) and highly recommend it. It’s been running great since 2016. 

6.2. Inverter/Charger


An inverter/charger combines an inverter and a battery charger. More info on this page:

6.3. Power Meter


To correctly size your inverter, you need to know the power consumption of the appliances you'll be taking with you in the van. You can normally find that information in the owner's manual, or you can use a Power Meter to find the real-world power consumption:

Power Meter
Power-Meter-Watt-Consumption

7. Monitoring


A battery/system monitor is optional, but we highly recommend it. You'll learn a lot about your power consumption, the actual status of your battery, and the impact of your charge source(s). For example, you can immediately see the effect of partial shading on solar and move to a better spot as required. In the end, it'll make you better at managing energy and optimizing the usage of your electrical system.

After reading this section, you will be able to:

  • Understand the role and functions of battery/system monitors.
  • Learn how monitors help managing your power.

7.1. Battery Monitor


A battery monitor function is to calculate and display real-time and historical data:

A shunt enables the battery monitor to make the measurement. It is typically installed between the battery bank and the negative bus bar:

We tested and recommend the Victron BMV-712 battery monitor, as it's a high-quality monitor with an excellent smartphone (BlueTooth) interface:

Victron BMV-712 Shunt & Display
Victron-BMV-712-Battery-Monitor
Shunt, display, and smartphone capabilities.
Victron Smart Shunt
Victron-Smart-Shunt-500A
Same as BMV-712, but without physical display (smartphone only).
Smartphone App
Victron-BMV-712-Status-annotated
Victron connect app

Here you will find our review about the Victron MPPT SmartSolar Charge Controller, the Battery Monitor, and the VictronConnect App. We also go through the installation, initial setup, and operation process. We have a bunch of cool screenshots and things to say about the Victron, so go read the article 🙂

7.2. System Monitor


The Simarine Pico system allows you to monitor much more than just the battery. It can also monitor the current draw of individual loadstank levels (fresh water, grey water, Nature’s Head, propane, etc.), temperatures (interior, exterior, fridge, etc.) and pitch/roll (inclinometer to park level). We installed it recently and we were blown away! The installation is more involving than a simple battery monitor, but here we have the full write-up (review, installation, etc):

Simarine Pico Tanks (500px)

8. Wires & Cables


The role of conductors (wires & cables) is to allow electricity to flow through them. While it seems pretty dull, this topic should not be overlooked as it is much more complex than it looks and is often the cause of various issues later down the road.

After reading this section, you will be able to:

  • Understand why stranded wires should be used in automotive/marine applications.
  • Understand the importance of selecting wires with correct temperature rating and ampacity.
  • Understand why and how to select the correct wire size (AWG).
  • Install wires in a way to minimize long term damage and prevent hazard.

8.1. Wire vs Cable


Let's get it out of the way. A wire is made of a single conductor/insulation, and a cable is made of several wires encased in sheathing (jacket):

Wire-vs-Cable-Electrical

That being said, both terms are often use interchangeably, so no need to go crazy with this :)

Wire
(Battery, Inverter, Charger, etc.)
Cable Inverter Welding Cable
GAUGEBuy Link (No Lug1)Buy Link (In Lugs2)
4/0 AWGNo LugIn Lugs
2/0 AWGNo LugIn Lugs
1/0 AWGNo LugIn Lugs
2 AWGNo LugIn Lugs
4 AWGNo LugIn Lugs
6 AWGNo LugIn Lugs
8 AWGNo LugIn Lugs
1 MANY LENGTHS AVAILABLE.
2 MANY LENGTHS / LUG SIZES AVAILABLE.
Duplex Cable
(Lights, Fan, 12V Outlets, etc.)
Ancor Marine Duplex Wire 14AWG

Useful to wire 12V loads, because it eliminates the need to route the positive and negative wire independently.

Marine-grade tinned copper duplex wire (6, 8, 10, 12, 14,16, 18 AWG) sold by the foot:

8.2. Solid vs Stranded


The conductor inside a wire can be either solid or stranded:

Stranded-vs-Solid-Cable
Solid Wire
Wire-Applications-Solid-House

Solid wire is made of a single solid metal core.

It is cheaper, offers more conductibility for the same diameter, and is more resistant to corrosion due to the smaller surface area. On the other hand, it is not intended to be flexed and not resistant to vibration and should not be used in mobile applications (marine/automotive).

Stranded Wire
Wire-Applications-Stranded-Van-RV-Boat

Stranded wire is made of thinner wires that are twisted together into a bundle.

Cost more and is less resistant to corrosion (that's why marine-grade wire is tinned). But it is very flexible and resistant to vibration, and is therefore the wire of choice in mobile applications (marine/automotive).

Again: Solid wires are for houses, not for moving vehicles (car, RV, boat). Because of the vibration and tight turning radius (when routing), the conductor in solid wire will most likely break in the long term.

8.3. Temperature Rating


Current passing through a conductor generates heat. More current, more heat. If the heat generated cannot be dissipated, the temperature of the conductor continues to increase until the cable exceeds its temperature rating and deteriorates, potentially creating a hazard.

Heat dissipation is influenced by the environment where the cable is installed. These are examples where heat dissipation is reduced, and oversizing the cables may be considered:

  • Cables carrying high current bundled together and into protective tubing (loom).
  • Cables buried in insulation.
  • Cables in very hot environment (e.g., attached directly to the ceiling of a dark van).
  • Cables carrying current continuously for long period of time.

Wires and cables are sold with different temperature ratings, commonly: 75°C, 90°C, and 105°C. A cable with a higher temperature rating has better insulation (material with better heat resistance) and can carry more current.

Marine wires and cables are typically rated at 105°C. The sizing tables and calculators to determine the correct AWG most often assume the use of 105°C cable; using lower temperature rated cable makes these tables and calculators wrong, as it cannot handle as much current. That's one of the reasons we highly recommend sticking with marine-grade wire!

8.4. Ampacity


The ampacity is the maximum current that a wire can carry continuously without exceeding its temperature rating. For example: if a wire has an ampacity of 45A (AWG 12) and there is a continuous current flow of more than 45A for an extended period of time, the wire could overheat and the insulation get damaged, creating a fire hazard. In the case of a short circuit where current is very high (still a real-world scenario), it could look a bit like this:

Cable-Fire-Short-Circuit
Short circuit experiment performed on a 12AWG cable in a 12V system. Credit: boathowto.com

An adequately sized overcurrent protection device (see Fuses and Breakers section) prevents from going over the ampacity rating of the wire (the fuse/breaker will trip before the wire get damaged).

In conditions where heat dissipation is reduced, the ampacity of a cable diminish. These conditions are referred as "derating factors" and results in a "derated ampacity", as seen in our wire gauge calculator:

8.5. Voltage Drop


There is a loss of energy (voltage drop) as current moves through passive elements (such as the wires, terminals, etc.) of an electrical system. Too much voltage drop could result in intermittent problems, such as the inverter "randomly" shutting off due to “battery low voltage”.

Remember the Ohm's law we introduce at the beginning of this guide? Here's a great example where the formula applies:

Voltage Drop (V) = Current (A) x Resistance (Ω/ft) x Length (ft)

  • Current: current flowing through the conductor.
  • Resistance: lenght-specific resistance of the conductor.
  • Length: 2-way length of the conductor.

So basically, in order to minimize the voltage drop, there are three factors to consider:

  1. Wire material. A material with better electrical conductivity offers less resistance (e.g. copper conducts electricity better than aluminum; this is why we recommend copper/tinned marine wires, and calculations through out our website is based on this type of material).
  2. Wire cross-section diameter (AWG). Smaller cross-section diameter offers more resistance and increases voltage drop.
  3. Wire length. Longer length offers more resistance and increases voltage drop.

We don’t have much control over the wire length. If a load is located far away, it is what it is, we need to reach it! We do, however, have flexibility over the wire material and cross-section diameter (AWG).

Generally, wire diameter should be selected to allow a maximum of 3% voltage drop for critical loads (panel main feeder, inverter, electronic) and 10% maximum voltage drop for non-critical loads (lightning, fan, etc.).

8.6. Size/Gauge/AWG


Choosing the correct wire gauge size allows to:

  1. Maintain voltage drop under a desired value (typically between 3% to 10%).
  2. Ensure current is below the ampacity rating of the wire.

A wire should always meet the two conditions above!

The American Boat and Yacht Council (ABYC) maintains a set of recommended practices and engineering standards for the design of electrical system on boats, which includes wire sizing. These requirements are found in ABYC E-09 document. It's a complex and lengthy read, pretty hard to digest. To make things easier, the following wire gauge calculator will output the correct wire gauge size based on ABYC E-09 standards:

Did you know that our Wiring Diagram features a built-in wire gauge calculator? So, you don’t actually need to size each wire individually… it doesn’t get any easier than this!

8.7. Installation


Should wires be installed Before or after the insulation?

As we've seen in Temperature Rating section above, the heat generated in the wires must be dissipated in the environment surrounding the wires. Otherwise, ampacity is derated.

So while hiding the wires inside the insulation looks like an elegant solution, it's not exactly ideal... indeed, it derates the ampacity of wires (heat can't dissipate) and it makes them hard to access (e.g., for troubleshooting, maintenance or adding more). We therefore prefer to install the insulation before, then install the electrical wires.

Securing the wires

Keep in mind that a moving vehicle is subject to intense vibrations. Wires and cables should be protected from chafing damage (abrasion) by securing them with split loom and rubber grommets as required:

Split Loom
Split Loom Tubing

The wires should be routed with split loom tubing.

Zip Ties
Zip Ties

Split loom is secured with zip ties.

Cable Clamps
Cable-Clamp-Kit-R-Type-Nylon-Black

Split loom is attached to wood with nylon cable clamps.

Zip Ties Mount
Zip Tie Adhesive Mount

Adhesive zip tie mounts can be used on metal (clean the surface with isopropyl alcohol).

Rubber Grommets
Rubber Grommet Kit

Rubber grommets protect the wire from sharp edges.

9. Terminals & Connectors


Electrical terminals and connectors are used to connect the wires/cables to other components (fuses, breakers, bus bars, battery, loads, etc.).

After reading this section, you will be able to:

  • Become familiar with terminal/connector materials, types and their uses.
  • Understand how to make connections that are solid and resistant to vibration.
  • Understand why terminals should be insulated.

9.1. Material


Terminals are commonly made of the following material:

Connectors-Type
Vinyl/PVC

One word: CHEAP. With this type of crimp, the wires remain exposed to the elements and can corrode. Moreover, the insulation can become brittle and crack over time. The vinyl/PVC are not great against pull-out. We pass.

Nylon

Like the Vinyl, the wires remain exposed to the elements. However, the nylon is more durable than the vinyl and is double-crimped, which provides more tensile strength and strain relief against pull-out.

Heat Shrink

The connector is crimped (single-crimp, because double-crimp might damage the insulation) and then heated to shrink the insulation around the wire and the melting adhesive adheres to the wire insulation. This provides a waterproof and permanent connection. Heat shrink connectors cost more, but there’s no price for safety and peace of mind!

9.2. Types


Below are the most common terminals with their respective usage:

Ring Terminals
(10 - 22 AWG, Heat Shrink)

Ring terminals are used to make "permanent" connections to fuse block, bus bar, etc. Make sure to choose the adequate wire gauge (AWG) and ring size:

Ring-Terminal-AWG-and-Ring-Size
Lug Terminals
(4/0 - 8 AWG, Copper)

Lug terminals are used for heavier gauge with heat shrink tubing (next section). Make sure to choose the adequate wire gauge (AWG) and ring size:

Lug-Terminal-Copper
Butt Connectors
(8 - 22 AWG, Heat Shrink)

Butt connectors are used to make a permanent connection between two exposed wire ends (e.g., wire splicing)

Ancor-Butt-Connectors-Heat-Shrink
Disconnects
(10 - 22 AWG, Heat Shrink)

Disconnects are used to make “non-permanent” connections (i.e. to our fridge, which we periodically pull-out to clean the back) and to connect to certain appliances (i.e. 12V Sockets, switches, etc.).

Disconnect

*Hint: Female disconnect should be on “hot” side of the wire (that’s the wire closest to the battery), male disconnect on the side of the appliance. This is to prevent short circuit when manipulating the “hot” wire.

Step-Down
(8 - 22 AWG, Heat Shrink)

Used as a step-down from one gauge size to another or as a multi-wire connector for one gauge size wire:

Step-Down-Butt-Connector-Ancor

9.3. Insulation


Any conductor left exposed (bare wire end, terminal, etc.) can potentially create a short circuit, therefore we highly recommend insulating when possible. Insulation provides the following benefits:

  • Prevent accidental short circuit.
  • Seal against moisture and other contaminants.
  • Prevent corrosion.
  • Add strain relief.
Heat Shrink Tubing
(1/8" - 1", Adhesive Lined, 3:1 Ratio)

Heat shrink tubing is commonly used on bare lug terminals:

Heat-Shrink-Tubing-Kit-Adhesive-3-1-Ratio-Red-Black
Bus Bar Cover

Make sure to include a cover when buying bus bars (you'll still need to cover the lugs with heat shrink tubing):

Bar-Bar-Cover-Blue-Sea
Battery Terminal Covers

Battle Born GC3 (270Ah) comes with covers, but unfortunately not the BB10012 (100Ah) ... We're open to suggestions for covering BB10012 flag-style terminals!

Battle-Born-GameChanger-GC3-Terminal-Covers

We are slowly working on designing and making enclosures and covers for the components we plan to use in our next van. It's still a work in progress at the time of writing these lines, but we'll add more to our Store as we go... Here is what we have so far: