DIY Van Electrical Guide: Build Your Knowledge

Van-Electrical-System-Design-Guide-(Heading-1920px)

DIY Van Electrical Guide: Build Your Knowledge

Our autonomy and comfort depend a lot on the electrical system of our DIY camper van conversion. No power means no fridge, no lights, no smartphone = no Instagram = no #vanlife as we know it 😛 Therefore, we want our electrical system to be safe, reliable and to work from the first time; trial-and-error is not acceptable here.

After two years on the road full time, we’re happy to report that our system works as we planned, nice! Designing the electrical system was one of the most intimidating task of the conversion process and if you’re reading this, you are probably looking for some guidance...

LAST UPDATE: JUNE 2020

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

1- Campervan Electrical System in a Nutshell

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

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

Camper Van Electrical System Nutshell

Makes sense so far, doesn’t it? Here is how all components work together to make a typical electrical system:

Our Wiring Diagram:

hover your cursor (desktop) or tap (phone/tablet) on each component to learn more.

Here it is in action:

Our Items List:

1- Inverter:
#ItemDescriptionQuantityView on Amazon
11000W InverterSamlex PST-1000-12 PST Pure Sine1View
2Remote Control for InverterSamlex RC-15A for 600W/1000W Inverter1View
3Cable, 2 AWG, 5 ft Black + 5 ft RedWindyNation1View
4Lugs, 2 AWG Cable, 5/16″ RingConnect to Terminal Fuse Block and Bus Bar (Pack of 2)1View
5Terminal Fuse, 175ABlue Sea (To protect inverter’s cable)1View
6Terminal Fuse BlockBlue Sea (Connects directly on the Bus Bar. Holds the Terminal Fuse)1View
2- Battery:
1LiFePO4 200 AhBattle Born LiFePO4 100 Ah 12V2amzn.to/2l6YuQQ
22/0 Cable in 5/16 lugs, 1 feet Red + 1 feet BlackWindy Nation Copper Cable1amzn.to/2D6EGFX
3- Solar:
1350W SolarNewPowa 175W Mono Panel2View
2Extension Cables, 8 AWG, 15 ft Red + 15 ft BlackWith MC4 Connectors1View
3Double Cable Entry GlandFor 8 AWG or 10 AWG Cable1View
440A Breaker/Switch, Surface MountBetween Panels and MPPT Charger1View
5MPPT Solar ChargerVictron 100|30 SmartSolar MPPT1View
640A Breaker/Switch, Surface MountBetween MPPT Charger & Battery1View
7Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ RingConnect to Bus Bar (Pack of 3)1View
8Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ RingConnect to Breakers (Pack of 3)2View
4- Alternator:
160A Battery-to-Battery Charger (B2B)Sterling Power BB12601View
2100A Breaker/Switch, Surface MountBlue Sea 285-Series2View
3Cable, 4 AWG, 15 ft Black + 15ft RedWindyNation1View
4Lugs, 4 AWG Cable, 5/16″ RingConnect to Bus Bar (Pack of 2)1View
5Lugs, 4 AWG Cable, 1/4″ RingConnect to Breakers (Pack of 2)2View
5- Shore:
150A ChargerSamlex SEC-1250UL 12V1View
260A Breaker/Switch, Surface MountBetween Charger and Bus Bar1View
3Cable, 8 AWG, 5 ft Black + 5 ft RedWindyNation1View
4Heat Shrink Terminal Ring, 8 AWG Cable, 1/4 RingConnect to Breaker (Pack of 3)1View
5Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ RingConnect to Bus Bar (Pack of 3)1View
6- Main:
1Terminal Fuse, 250ABlue Sea (Catastrophic Fail Safe)1View
2Terminal Fuse BlockBlue Sea (Connects directly to battery post. Holds the Terminal Fuse)1View
3System SwitchBlue Sea (Main System Switch)1View
4Bus Bar (250A, 4 studs)Blue Sea2View
5Cover for Bus Bar (for 250A 4 studs)Protect the Bus Bar2View
640A Breaker/Switch, Surface MountBetween Fuse Block and Bus Bar1View
7Fuse Block (12 circuits)Blue Sea (12V Distribution Panel)1View
8Fuses KitAssorted Fuses (2A 3A 5A 7.5A 10A 15A 20A 25A 30A 35A)1View
9Battery MonitorVictron BMV-712 with BlueTooth1View
10Cable, 2/0, 5 ft Black + 5 ft RedBetween battery and Bus Bar1View
11Lugs, 2/0 Cable, 3/8″ RingConnect to System Switch and Shunt (Pack of 5)1View
12Lugs, 2/0 Cable, 5/16″ RingConnect to Bus Bar, Terminal Fuse Block and Battery (Pack of 5)1View
13Cable, 8 AWG, 5 ft Black + 5 ft RedBetween Bus Bar and Fuse Block1View
14Heat Shrink Terminal Ring, 8 AWG Cable, #10 RingConnect to Fuse Block (Pack of 3)1View
15Heat Shrink Terminal Ring, 8 AWG Cable, 1/4″ RingConnect to Breaker (Pack of 3)1View
16Heat Shrink Terminal Ring, 8 AWG Cable, 5/16″ RingConnect to Bus Bar (Pack of 3)1View
17Heat Shrink Tubing Kit (with adhesive)To protect lug after crimping1View
7- Hardware:
112 AWG Black/Red Duplex Cable (12/2), Ancor Marine Grade100 feet1View
214 AWG Black/Red Duplex Cable (14/2), Ancor Marine Grade100 feet1View
3Heat Shrink Terminal Ring, 12 AWG Cable, #8 RingTo connect to Fuse Block (25 Pack)1View
4Heat Shrink Terminal Ring, 14 AWG Cable, #8 RingTo connect to Fuse Block (25 Pack)1View
5Heat Shrink Butt Connector, Ancor MarineTo connect to Loads (75 Pack Kit)1View
6Heat 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)
1View
7Heat Shrink Disconnect, 10-12 AWG Cable, 1/4″ Tab, Male1View
8Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Female1View
9Heat Shrink Disconnect, 14-16 AWG Cable, 1/4″ Tab, Male1View
10Heat Shrink Disconnect, 18-22 AWG Cable, 1/4″ Tab, Male1View
113M Scotchlok Quick Splice with Gel (14 AWG stranded)We used that to parallel our LED lights (25 Pack)1View
12Split Loom Tubing, 3/8″ diameter 20 feetTo protect wire bundles1View
13Split Loom Tubing, 1/2″ diameter 20 feetTo protect wire bundles1View
14Split Loom Tubing, 3/4″ diameter 20 feetTo protect wire bundles1View
15Nylon Cable Clamps KitTo secure cable/split-loom to wood1View
16Zip Tie Mount with AdhesiveTo secure cable/split-loom to metal1View
17Nylon Zip Ties KitTo secure cable/split-loom1View
18Rubber Grommet KitTo protect wire from sharp edge (going through metal hole)1View
8- 12V Loads:
1Maxxair 6200K Roof FanSee our Installation or Review article1amzn.to/2qJCbA1
2LED Ceiling LightsSee our Installation and Review article3amzn.to/2vpyyVs
3Dimmer for LED (PWM), 12V, SliderTo control intensity of LED lights1amzn.to/30dDyak
4Blue Sea 12V Socket 4amzn.to/2JVPypv
5Shurflo Revolution Water Pump, 3 GPMSee our Installation article1amzn.to/2J9NqZQ
6ON/OFF Switch for Water Pump 1amzn.to/2Oiyhvy
7Webasto Air Top 2000 STC Gasoline HeaterSee our Installation article1eBay
8Propex HS2000 Propane HeaterSee our Installation article1eBay
9Novakool R5810 Fridge, 12V only5.8 cubic feet1Campervan-HQ
10Sirocco ii Gimbal Fan, 12VSee our Review article1amzn.to/2HKy7HR
11Nature’s Head Composting ToiletSee our Installation or Review article1amzn.to/2qJOsEA
12Propane Solenoid Shutoff ValveSee our Propane System Guide1eBay
13ON/OFF Switch for Propane SolenoidSee our Propane System Guide1amzn.to/2LB5Gjr

Well, that escalated quickly… If you can’t “read” the wiring diagram above, don’t give up just yet. Keep reading to build your knowledge and work your way up! Be patient, sleep on it; it might takes multiple reads before it all starts to make sense…

2- Battery Bank

Because power from the charge sources is not available at all time, 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. 

2.1- Battery Types

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

Flooded Lead-Acid
Gel-Cell
AGM
Lithium (LiFePO4)

Unless your budget is very critical, we don’t really recommend flooded lead-acid or GEL (because of the maintenance aspect). That brings us to our next topic:

Choosing between AGM or Lithium (LiFePO4) Battery in 2019

When we built our van in 2016 (researching and designing during 2015), AGM was the obvious choice because  it was a tried-and-true option (good performances, safe & reliable). Lithium (LiFePO4) batteries were a relatively new thing (in the van/RV world) and we were concerned about reliability & safety (and cost!). Technology advance so let’s see if, 4 years later, our concerns have been addressed:

1- B.M.S. (Battery Management System)

There are a few scenarios where it could be unsafe to operate a LiFePO4 battery:

  1. Temperature too low / too high;
  2. Voltage too high;
  3. Current too high.

To mitigate these scenarios companies like Battle Born Batteries, Trojan, Relion, Victron, now include BMS (Battery Management System) built-in their batteries. The BMS is in charge of watching if parameters (temperature, voltage, current) are within safe range. For example, the BMS will prevent charging the battery if the temperature is too low; it will also regulate the amount of power you can take out of the battery. It makes using a Lithium battery safe.

2- Lithium batteries can't be charged below 32F/0°C (more or less)

That’s quite an issue for us, knowing we use our van for skiing all winter (faroutride.com/winter-vanlife). An AGM battery do better in that department, but still performs better around room temperature; that’s the main reason why we installed our AGM battery inside the van. Because we live full-time in our van, we never let the interior freeze (because food/liquid/comfort) so that solves the issue for us!

Note 1: While LiFePO4 cannot be charged below freezing temperatures, they can still be discharged. So it would be possible to install a 12V heat mat to prevent the battery from freezing…

Note 2: In fact, some brand of Lithium batteries can be charge below 32F/0°C, but at a slower rate. Check your battery specification sheet!

3- AGM vs Lithium Comparison

Let’s compare our actual Rolls AGM battery (210Ah) to a BattleBorn LiFePO4 battery bank (100Ah). What really matter here is the “Actual Capacity Available” (remember that ideally an AGM should not be discharged below 50% of its capacity); so that’s why we compare a 210 AGM to a 100Ah Lithium:

  210Ah AGM 100Ah LITHIUM
ACTUAL CAPACITY AVAILABLE 105Ah 100Ah
WEIGHT 133.5 lbs 31 lbs
TOTAL LIFE CYCLE* 1200 3000
UPFRONT COST $650 $950
COST PER CYCLE $0.54 $0.32
LENGTH 21" 12.75"
WIDTH 8.5" 6.875"
HEIGHT 9.5" 9"
*Assuming a D.O.D. (Depth-of-discharge) of 50% for AGM, 100% for LiFePO4.

For full-time Vanlife (1 full cycle daily), it means an AGM will cost roughly $200 per year to operate and will last 3.5 years; while a Lithium will cost roughly $120 per year to operate and will last 8 years.

Soooo, AGM or Lithium?

If we had to start over (in 2019), we would go for Lithium (LiFePO4). Oh wait… as of June 2019 we just upgraded to Battle Born Lithium batteries (2 x 100Ah)! We LOVE staying up-to-date with technology and we enjoy testing products, so we made the leap 🙂 Our first impressions:

  • These things are crazy light weight!
  • They reach 100% SOC much faster than the AGM (absorption phase in AGM occurs quite slowly), and keep in mind we made no change to our solar & alternator charging. That means more power, faster. Nice.
  • Since we have two batteries in parallel, we can charge up to 100A if we upgrade our b2b charger (right now we have a 60A b2b charger); that could be nice for winter.
  • So far so good, highly recommended!*

*Note: We would NOT go for Lithium if our battery bank was installed outside the van (too cold during skiing season).

Replace Rolls AGM with Battle Born Batteries Lithium
New Battle Born Batteries ready for installation!
Budget
3/5
Renogy 50/100/170Ah Lithium (LiFePO4) 12V Battery
(2000 cycles life, 100A COntinuous Discharge Current)
Quality/Price
4.5/5
Battle Born Batteries 100Ah Lithium (LiFePO4) 12V
(3000 cycles life, 100A CONTINUOUS DISCHARGE CURRENT)
High-End
5/5
Trojan 110Ah Lithium (LiFePO4) 12V
(4000 cycles life, 110A continuous discharge current)

Quick interruption: Our Opinion About Product Quality

"You get what you pay for"
Cheap
0.5/5

What differentiate the “cheap” products (unbranded, very cheap products on Amazon & eBay) from the “Budget” products:

We took our chance with cheap products on non-critical components (radio unit, inclinometer, electrical connectors when we ran out of the good ones –> we replaced them with good ones afterwards!) and the result is always the same: product doesn’t last long, it’s buggy and has to be replaced soon enough. Even if the low initial cost is very appealing, we will NEVER recommend a cheap product for the electrical system (or else); we’re not rich enough to constantly replace our stuff.

Budget
3/5

This is our entry-level. To save cost, budget products typically don’t use the best internal components and consequently don’t show the best performance and durability. We recommend products within that category if budget is your priority.

Brands that fall into that category:
Quality/Price
4.5/5

This is our mid-level and most components in our van stand within that range. We don’t mind paying more initially if the product delivers good performances and last in time. We think it’s the best bang for the buck.

Brands that fall into that category:
High-End
5/5

This is the “pro-level”. Products within that range deliver the ultimate performances. It’s pricey but for critical components of our electrical system, there’s no price for peace of mind.

Brands that fall into that category:
OK we're done, thanks for listening!

2.2- Specifications

Not all batteries are made equal! A cheap battery won’t be able to give as much current as a high-quality battery… it is YOUR responsibility to make sure you’re not going overboard, so read the spec sheet! Any reputable brand should publish one for each of its product. Cheap products often don’t publish spec sheet; that a good enough reason not-to buy their products!

Here is  an example of how a spec sheet should be (click the image to view the pdf):

Relion Specification Sheet (1 of 2)
credit: relionbattery.com/products/lithium
credit: relionbattery.com/products/lithium

Information is clearly shown, it’s straight-to-the-point, there is no marketing sales pitch… well done Relion! More examples: Trojan, BattleBorn (they really need to step up their game…), Rolls.

Information to look for:

2.3- Combining Batteries

While we prefer to use a single battery, batteries can be wired together in parallel or series. In both cases:

  • You should always use identical batteries (brand/capacity/age) so they work equally together.
  • You should always use identical cables (length/diameter) so they offer the same resistance, ensuring all batteries work equally together.
Parallel

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
photo credit: enerdrive.com
Series

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

series-battery-connection
photo credit: enerdrive.com

2.4- Charge Profile

Charging a battery is NOT like filling a car with gas…

  • With a car, bringing the fuel gauge up to 100% is all that matters. Then, maintain your car periodically (oil change) and it’ll be running smooth for a long time 🙂
  • With a battery, how you bring it up to 100% really matters: you are filling it and doing the maintenance simultaneously!
Fuel-Gauge-Cross

An adequate charge cycle 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 brand (Rolls, Trojan, BattleBorn, etc) requires different charge profile.  Why you should care about charge profile:

Lead-Acid (Flooded, Gel, AGM)
Typical Charge Profile
Stage 1: BULK

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

Near 85% the battery become 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

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

Lithium (LiFePO4)
Typical Charge Profile

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!

Stage 1: BULK

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

Stage 2: ABSORPTION

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

Stage 3: FLOAT

Consult the specification sheet of your battery brand/model to find its specific charge profile!

2.5- Discharging Batteries

We’ve just seen how charging a battery impact its life cycle & performance. Discharging a battery has similar implications; let’s see how!

Terminology

State Of Charge (SOC)

It is defined as “how fully charged” the battery is.

Depth Of Discharge (DOD)

It is defined as “how deep” the battery is discharged. (it’s the opposite of SOC…)

CYCLE

In a typical usage, a battery starts fully charged (100% SOC), then goes down to a certain level (e.g. 80% SOC), back to fully charged (100% SOC). This is defined as a cycle

A cycle is independent of calendar, so there could be multiple cycles per day or one cycle per week… But typically, a campervan/RV battery cycles once per day because of solar power.

CYCLE Life

The life span of a battery (how long it will last) is mostly defined by the number of cycles… in a similar way that mileage defines the life cycle of cars.

As a battery ages (cycles), it holds less and less energy. Generally, manufacturers consider that a battery has reached its end of life when it cannot hold more than 70% of its initial capacity (i.e. eventually, a 100Ah battery becomes a 70Ah battery).

Charge/Discharge Rate

It is defined as how fast (current) a battery bank is charged/discharged. 

“0.2C Rate” means 20% of the battery bank capacity; “0.5C Rate” means 50% of the battery bank capacity; and so on. For example if the battery bank is comprised of 2 x 100Ah Battle Born Batteries, “0.5C Rate” =0.5 x 200Ah = 100A.

Discharge Current Rate

1- Its Capacity:
Features / Setup / Installation / First Impressions: faroutride.com/simarine-pico
(credit: BattleBorn Batteries)

A Lithium battery (black curves) is able to deliver pretty much the same amount of energy regardless of how fast it’s being discharged, as opposed to a lead acid (red curves).

2- Its total life cycle:
Trojan Trillium LiFePO4 Life Cycle
(credit: Trojan)

Discharging a battery more rapidly will reduce its total life cycle (AGM or Lithium).

Depth Of Discharge (D.O.D.)

Trojan Trillium Lithium (LiFePO4):
Rolls AGM:

For full-time Vanlife, a battery will typically sees 365 cycles per year. But keep in mind that while cycle life plays a major role in the life span of the battery, calendar also has an impact as materials (used to chemically store energy) degrade over time. Many factors influence degradation, temperature being one of the most important. 

2.6- Temperature

Generally, batteries perform better near room temperature. For example, take electric cars: their range in 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

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 electrolyte becomes 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! Consult your battery manual.

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

Specific Gravity

(SG)

State of Charge 

approx (%)

Freezing Temperature

C (F)

1.280100-69C (-92F)
1.26592-57.4C (-72.3F)
1.25085-52.2C (-62F)
1.20060-26.7C (-16F)
1.15040-15C (5F)
1.10020-7C (19F)
Lithium (LiFePO4)

We often hear that a lithium battery cannot be charged below 32F (0°C); In fact, some brand of Lithium batteries can be charge 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.

Charging A Battery At High Temperature

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

3- Charge Sources

Now that we understand how to properly charge a battery, let’s see our charge options:

3.1- Solar Power

Harvesting power from the sun feels a bit like cheating to us; this is the exciting part of the electrical system! It is free to use, but it is not exactly cheap to setup at first.

First of all, do you really need solar power in your system? If you’re thinking on charging only from the alternator, keep in mind that while the bulk charge is relatively fast, it takes a long time to complete the absorption stage (even if you have a powerful charger). So unless you like to drive A LOT everyday, solar power will ensure you get a full charge and will increase your battery life!

3.1.1- In a Nutshell

For example, here is a screenshot from our Victron solar charge controller (faroutride.com/victron-review). Notice how the voltage/current coming out of the panels are different from the voltage/current going into the battery:

3.1.2- Monocrystalline or Polycrystalline?

Monocrystalline used to be more efficient than polycrystalline, but it’s not so true anymore. The quality of the solar panel (manufacturer) is more important than the type of the panel. Here is a good article if you want to learn more about that: Pros and Cons of Monocrystalline vs Polycrystalline solar panels.

Renogy 100W Solar Panel 12V
(41.6"x20.7"x1.38")
Newpowa 175W Solar Panel 12V
(58.4"x26.6"x1.38")
Renogy 300W Solar Panel 24V
(64.9"x39.3"x1.6")

3.1.3- Combining Multiple Panels

Series
No adapter required.
Parallel
Solar-Panels-Parallel-Connection
Parallel adapter required.

Partial shading is not a myth, but unfortunately professional solar installers (or DIYers) seem to ignore that a lot, judging from how solar panels are installed relative to the fans/roof racks… Take the time to read the next section!

3.1.4- Partial Shading

Blocking a single cell from a solar array can completely bring the solar output down to ZERO. That’s right! Bear with us…

Solar Panel Construction

Solar panels are made of multiple solar cells all connected together in series; blocking one of the cell totally kills the output of the solar panel. Think of the old Christmas tree lights: if one of the bulb blew, the entire thing would go off. Meh. Typically we see roof racks or fans creating partial shading (this is totally avoidable!):

Solar-Partial-Shading-from-Roof-Fan
This panel gives 0% output (assuming it has no bypass diode)
Solar Array

What if the solar panel above is part of an array connected in series? The resulting total power is ZERO. See the water analogy below:

photo credit: blog.aurorasolar.com
Shaded-Cell-as-Clog-in-Pipe-Fan
photo credit: blog.aurorasolar.com
Bypass Diodes

Fortunately, modern solar panels have built-in bypass diodes that helps with partial shading. In such solar panel, 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 Panel Blocked Cell bypass diode
Here, the panel give 50% output thanks to the bypass diode.

Don’t celebrate too fast: even with bypass diodes, a solar array (in series) total power will be considerably reduced:

Solar-Array-Series-Blocked-Cell

In the example above:

Total Power Without Partial Shading
0 Watts
(57V x 9A)
Total Power With Partial Shading (Series)
0 Watts
(57V x 4.5A)
Total Power With Partial Shading (Parallel)
0 Watts
18V x (9A + 4.5A + 9A)
Conclusion on partial shading

And that explains our roof layout:

Cleaning the solar panels 2

3.1.5- Panel Orientation

A panel will deliver more current if oriented perpendicular to the sun. On large commercial solar plant, the panels are mounted on a motor-driven device that will optimized 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. But with our lifestyle we generally move a few times each day, so we personally don’t feel like it’s worth the hassle.

At last, having several panels with dissimilar orientation has a similar effect as partial shading. If you must have dissimilar orientation, consider connecting your panels in parallel.

3.1.6- Solar Charge Controller

MPPT vs PWM

MPPT are more efficient than PWM in cold temperature, partially sunny day and if the voltage of your solar panels is superior to the voltage of your battery bank. However they consume a small amount of power for themselves (it’s almost nothing really) and are more expensive than PWM. The debate rage about the MPPT efficiency over PWM, but it is believed to be around 10%-20% more efficient depending on the conditions.

MPPT VS PWM, What Others Have to Say:

  • See Bogart Engineering take on MPPT vs PWM charge controller debate here (see FAQ “C1″)
  • MorningStar MPPT vs PWM comparison.
  • Victron MPPT vs PWM: Which solar charger to choose?
  • Side-to-side, real world testing of MPPT vs PWM charge controller here.

MPPT VS PWM, What We Have to Say:

  • We first installed a PWM charge controller (Bogart Engineering) and then upgraded to a MPPT (Victron SmartSolar).
  • While we can’t exactly quantify the improvement, we immediately noticed more charging current; we observed 24A with the Victron while the most we got with the Bogart was 16A.
  • We also noticed more power earlier in the morning and during overcast weather.
  • OK we’re sold to the Victron MPPT!!

Here you will find our review about the Victron MPPT SmartSolar Charger, Battery Monitor and 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 🙂

Choosing the size of the Charge Controller

All Victron solar charge controllers are denoted by MPPT XXX | XX:

Victron-SmartSolar-100_30_Legnd

Choosing the size of the charge controller is also covered in our “Victron Review” above 🙂

3.2- Alternator

When driving, the alternator role 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 “borrow” electrical energy from the alternator to charge the house battery…

Do you need alternator power in your system? It depends:

  • If you live full time in your van, we say it’s a must. Energy is a basic need, it’s not cool worrying about running out of it…
  • If you take your van for adventures in summer only, you can probably live without it.
  • For fall and spring adventures, we highly recommend it as the solar days get shorter and weaker. Alternator power is a good way to quickly go through the bulk charge, then solar power can complete the absorption stage.
  • For winter there’s no question about it, our opinion is that you want it.
3.2.1- Isolator / Automatic Charging Relay (ACR)

Isolator and ACR combine the starter battery and the house battery together during the charge and disconnect them during discharge. 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. That’s not great for the cycle-life of lead-acid batteries (flooded, gel, AGM) and they tend to overwork alternators, so we prefer the B2B option.

Blue Sea ACR with Manual Control (up to 500 amps alternator).
Lithium Battery Isolation Manager (Up to 225A)
To prevent overworking the alternator, this device cycles 15 minutes "ON" then 20 minutes "OFF".
3.2.2- Battery to Battery Charger (a.k.a. "B2B" or "DC to DC")

This option is quite popular these days as it provide many advantages:

  1. It’s a Smart Charger, meaning it provides a multi-stage charge adapted to the battery type (Gel, AGM, LifePO4, etc). That’s important, because it will keep your house battery healthy and maximize its lifecycle (especially for lead-acid batteries “flooded, gel or AGM”).
  2. It acts as current limiter to prevent overworking the alternator (choose between various models: 30A, 60A or 120A).
  3. Easier to install: no need to wire to the vehicle ignition.
  4. It’s plug-and-forget: the B2B will automatically activate/deactivate when driving to keep the house battery topped up.
Budget
3/5
Renogy DC to DC charger
(20A or 40A)
Quality/Price
4.5/5
CTEK D250SA
(20A or 80A with Smartpass. Also acts as solar charge controller)
High-End
5/5
Sterling Power Pro Batt Ultra
(30A, 60A or 120A)
3.2.3- Accessing Battery Power (alternator power) on the Ford Transit

Please check this official Ford SVE Bulletin on how to use the battery power (alternator) on SINGLE or DOUBLE battery variant: SVE Bulletin Q-226 (.pdf)

3.2.4- Accessing Battery Power (alternator power) on the Mercedes Sprinter
Sprinter Power Tapping Option 2 (page 1)
Sprinter Power Tapping Option 2 (page 2)

THE PICTURES ABOVE ARE EXTRACTED FROM THE BODY AND EQUIPMENT GUIDELINE, PAGE 246, 247 & 248. MAKE SURE TO READ THESE PAGES FOR MANUFACTURER RECOMMENDATIONS AND LIMITATIONS:

3.3- Shore Power

Do you need shore power in your system? We think it’s a good option if:

  • You spend extended time in campgrounds with full service.
  • You use your van to chase the snow. Indeed, solar is VERY weak in winter and it takes a LONG drive to complete a full charge so it’s sometimes required to plug in for the night.
3.3.1- Battery Charger / Converter

A smart Battery Charger / Converter will:

  1. Charge the house battery from a 120V source by providing a multi-stage charging profile adapted to the battery type (Gel, AGM, etc).
  2. Provide power to 12V loads. This means using 12V loads (refrigerator, lights, etc) won’t discharge the battery when the charger/converter is plugged in.
Samlex 12V Smart Battery Charger / Converter.
15A/30A/50A/80A
3.3.2- Inverter / Charger

An inverter / Charger is a battery charger AND an inverter combined into one device. It is quite convenient because it simplify the installation (one device instead of two), but it’s more expensive (between 1000$-2000$ for high-quality ones) than installing a separate inverter and a battery charger…

Budget
3/5
Renogy Pure Sine Inverter/Charger (2000W).
Quality/Price
4.5/5
Victron MultiPlus Compact Pure Sine Inverter/Charger (2000W).
High-End
5/5
Magnum Pure Sine Inverter/Charger (2000W).

4- 12V DC Loads

Installing appliances and devices that work on 12V DC is efficient, because there’s always a loss when converting to 120V AC. Here are all the 12V loads we’re running in our van:

Shurflo Revolution Water Pump, 3 GPM
Novakool R5810 12V Compressor Fridge
Webasto Air Top 2000 STC Gasoline Heater
Propex HS2000 Propane Heater
Sirocco II Gimbal Fan
Propane Solenoid Shut Off Valve

5- 120V AC Loads

The role of the inverter is to convert the voltage from 12V DC to 120V AC. Just remember that there is a loss of around 15% efficiency during the conversion from DC to AC, so try to avoid it when possible. For example, get a 12V power adapter to power your laptop, phone, camera, etc:

Laptop Car Charger
(make sure it's compatible with your laptop)
Phone Car Charger

Now, there are some appliance that must use 120V AC such as microwave, gaming laptop, milk frother, blender, coffee machine, etc. In that case, you will need an inverter. You should size your inverter according to your most demanding appliance; check the owner manual or check online to find out how much Watt an appliance draw. If you can’t find the info, you can use a Kill-a-watt. The Kill A Watt is plugged into the 120V outlet (of your house), then the appliance is plugged into the Kill A Watt and then the consumption will be displayed.

Kill A Watt

And remember that a microwave rated for 1500W will most likely draw more than 1500W… so get a 2000W inverter.

Modified VS Pure Sine Inverter

There are two types of inverter: modified and pure sine inverter. This short but comprehensive article makes a good job at explaining the differences and there’s a list of appliances that might not work with a modified sine wave inverter: https://www.samlexamerica.com/support/faqs/faq02.aspx

In a nutshell:

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:

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. 

About Power Rating

Normally inverters are 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 draw on the 12V DC side (battery). For example, a 1800W inverter will draw more than 1800W on the DC side:

Power-Inverter-Rating-Efficiency

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. 

Budget
3/5
Renogy Pure Sine Inverter
Quality/Price
4.5/5
Xantrex Pro Power Inverter 1000W 1800W
Xantrex Prowatt SW Pure Sine Inverter
High-End
5/5
samlex-pst-1000-inverter
Samlex Pure Sine Power Inverter

High Current!

Remember that inverters draw HUUUUGE amount of current (i.e. 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 loose over time/vibration) or else, enjoy the fireworks. In doubt, ask a professional to install/verify it for you.

6- Battery and System Monitoring

6.1- Battery Monitor

A battery monitor is not mandatory, but we strongly recommend it. Depending on your model, it will display the house and van battery voltage, amperage coming in/out of the house battery,  % battery left, amperage used since last charge, etc, etc. You will learn a lot from the battery monitor on: 1- the impact of shade on solar (and help you choose the right parking spot) 2- the impact of your load(s). This will help you better manage your energy. We tested and recommend the Victron BMV-712 because it’s a modern, high-quality monitor:

Victron BMV-712 System Monitor

The Victron BMV-712 has bluetooth inside and current status (and historical data) can be displayed on an iPhone or Android phone!

Here you will find our review about the Victron MPPT SmartSolar Charger, Battery Monitor and 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 🙂

6.2- System Monitor

The Simarine Pico system monitor enables to monitor much more than just the battery. It can also monitor the consumers (current consumption of individual loads), tank levels (fresh, grey, Nature’s Head, propane, etc), temperatures (interior, exterior, fridge, etc) and pitch/roll (inclinometer to park level). We installed it recently and we’re blown away by the quality of that thing! Not to mention it is VERY sexy and looks much better in our van than any other monitor 🙂

Simarine Pico System Monitor: Installation, Setup and Review

7- Electrical Wiring

7.1- Wire Diameter (AWG)

Choosing the correct wire size (AWG) is essential for SAFETY (fire hazard due to ampacity) and PERFORMANCE (intermittent problems due to voltage drop) of your electrical system.

7.1.1- Ampacity

The ampacity is the maximum current that a wire can carry continuously without exceeding its temperature rating. For example: if a wire ampacity is 60A (AWG 10) and there is a continuous current flow of 61A, the wire will overheat and the insulation could melt, creating a fire hazard. An overcurrent protection device (fuse/breaker) prevents going over the ampacity rating of the wire (the fuse/breaker size should always be smaller than the wire ampacity).

7.1.2- Voltage Drop

There is a loss of energy (voltage drop) as current moves through passive elements (wires, terminals, etc) of an electrical system. The wires are a big contributor to the voltage drop and this should be taken into account when designing the electrical system. How? By selecting the appropriate diameter; the bigger the diameter, the smaller the voltage drop. Generally, wire diameter should be selected to provide 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). That being said, we personally like to use around 3% voltage drop for everything in our van.

7.1.3- Selecting the correct wire diameter

Now, really, how do you selected the correct wire diameter? It can be done manually by following ABYC standards (ABYC E-09 1990 pdf), but to make your life easier we designed this WIRE GAUGE CALCULATOR:

Making things easy:

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 that this!

7.2- Wire Type

Electrical wire is made of a conductor inside an insulator. There are two types of wire depending on how the conductor is made:

Stranded-vs-Solid-Cable
Stranded
Solid

Solid wire is commonly found in houses, not in 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. Therefore, it is mandatory to use copper stranded wire that’s rated for 105°C (lower rated temperature cannot handle as much current, so it invalidates the wire sizing per ABYC):

 
Primary Wire
(Battery/Inverter/Charger/etc)
GAUGENo Lug1In 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 Wire
(6/2 AWG up to 16/2 AWG)

7.3- Wire Crimping

There are many ways to connect wires together or to a terminal. We will go straight to the point here, the best way to do it is crimping. Crimping will deform the connector into the wire and ensure a solid permanent mechanical connection with low resistance. To crimp, you need quality crimping tools and quality crimp connectors. 

7.3.1- Crimp Connectors

There’s 3 types of 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 are more expensive, but there’s no price for safety and peace of mind!

We recommend the Ancor, marine-grade connectors:

Terminal Ring

Terminal rings are commonly used to make connections to the fuse block, battery, etc.

Butt Connector

Butt connectors are commonly used to make a permanent connection to an appliance.

Disconnect

Disconnects are commonly 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).

*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.

7.3.2- Tools

Quality tools = safe and durable electrical system. Do not use pliers as you will get poor connections = safety and reliability issues.

Ancor Single-Crimp Tool (8 - 22 AWG)
Ancor Single Crimp Tool
(for vinyl & heat shrink connectors)
Ancor Double-Crimp Tool (10 - 22 AWG)
Ancor Crimp Tool
(for nylon insulated connectors)
Ancor Wire Cutter and Stripper
Hydraulic Crimper (2/0 - 12 AWG)
Cable Cutter (Up to 4/0 AWG)
Heat Gun (for heat shrink)
Digital Multimeter
Electrical System Installation Van Conversion (4)
You shall make your crimp-face when crimping.

7.4- Wire Installation

Before or after the insulation?

Current flowing through a wire generates heat. In steady state (after a long and continuous usage), the wire must be able to evacuate as much heat as it generates. Otherwise the temperature inside the wire keeps increasing, leading to a few possible problems:

  1. Resistance of a conductor increases with temperature. In other words, higher temperature equals more voltage drop.
  2. The maximum current that a wire can carry continuously without exceeding its temperature rating is called “ampacity”. Installing a wire inside insulation reduces the ampacity rating of a wire by approximately 30% (it’s huge!), because the ability of the wire to evacuate heat is greatly reduced. For example, a 6 AWG copper rated for 105°C can normally carry 120A continuously, but if it’s buried in insulation it can only carry 84A continuously.  Going over 84A will overheat the wire and create a fire hazard.
So while hiding the wires inside the insulation looks like an elegant solution, it’s far from ideal; indeed, it reduces the performance of the electrical system and increase safety hazard. We therefore recommend insulating first, then after installing the electrical wires. We know it makes things more complicated, but it is what it is (it’s physics we can’t deny that).

Securing the Wires

For safety sake, the wires should not be installed loose and unprotected; as opposed to a house, there is a lot of vibration and movements that will damage the wires in the long run.

The wires should be routed through Split Loom Tubing (make sure to buy several diameters) attached with zip ties.

To route a wire through a metal hole, always use a rubber grommet to protect it from the sharp edges.

Split Loom Tubing
Split Loom Tubing
The wires should be routed through Split Loom Tubing (make sure to buy several diameters).
Zip Ties
Zip Ties
The split loom attached with zip ties.
Cable Clamps
Cable-Clamp-Kit-R-Type-Nylon-Black
The split loom attached to wood wall with nylon cable clamps.
Adhesived Zip Ties Mount
Zip Tie Adhesive Mount
Adhesived zip tie mounts can be used on metal (clean the surface with isopropyl alcool first).
Rubber Grommets
Rubber Grommet Kit
Rubber grommets protect the wire from sharp edges.

8- Fuses and Breakers

Fuses and breakers are essential in any electrical system! It will protect the circuit wires and the components against over current and ultimately fire. If you blow a fuse during your system installation (we did a few times), it means that you just avoided a potential failure or fire! Nice!

In our wiring diagram, every positive wire has a fuse or a breaker to prevent going over the ampacity (max current rating) of the wire. To select the correct fuse/breaker size, consult the owner’s manual of the load or use our calculator above. To keep things neat and organized, a fuse block is used for all our 12V loads:

Blue Sea Fuse Block

The fuse will drive the wire diameter selection. For example, if wiring a load that draw 5A and a fuse of 15A is used, you should choose a wire with ampacity rating (max current rating) of more than 15A! This is safety matters.

Breakers are similar to fuses, except that if it blows it is possible to reset it without replacing it. Fuses generally blow faster than breakers and therefore fuses are preferred for sensible electronics. We added a few 40 amp breakers in our system. Why? First, to avoid having to use big electrical wires. Indeed, our fuse block is capable of 100A; even if we know that we will never draw 100A, we need to size our wires for 100A ($$$). By adding 40A breakers, we can size our wires for 40A. We can also turn off portion of the system by switching a breaker off (for example, turn off solar panels to display on our system monitor the draw that the loads are pulling. Or the opposite to display the charge that the solar panels are providing).

Here is a more complete article about this topic: http://www.12voltplanet.co.uk/fuses-guide-uses.html

Connecting the Blue Sea 285 breakers:

We recommend the Blue Sea 285 Series breakers. On the breaker, you’ll find a terminal labeled as “AUX” and a terminal labeled as “BAT”. For this type of thermal responsive breaker, it does not matter how it is connected. BUT this is not the case for all breakers, so be careful and check for each type of breaker.

9- Short and Long term Van/RV Storage

Not planning on using your van for a while? Then you’ve got a few things to do in order to maximize your battery lifespan! For either short-term storage (weeks) or for long-term storage (months), here are our recommendations:

Loads & Charge Sources
Battery SOC
Temperature
Storage Mode for Lead-Acid (flooded, gel, AGM):
Storage Mode for Lithium (LiFePO4):

10- Power "Generator" (Goal Zero, Kodiak, etc)

Designing and building an electrical system is far from an easy task, so Power “Generators” (thanks marketing people for this confusing term… how about “Power Station” instead?) seems like a simple alternative, right? Well, it depends. 

We think it’s a great solution for photographer (for example) working and living for short stretches in their vehicle:

However, we don’t think they’re really meant for a “true” van electrical system, because they have far too many limitations:

Aware of the pros/cons? Still think it’s the adequate solution for you? Awesome! Here are the latest Power Stations from Goal Zero:

Yeti 400 Lithium
Yeti 1000 Lithium
Yeti 1400 Lithium
Yeti 3000 Lithium
Boulder Solar Panel

11- Real World Data

11.1- Measured Summer Daily Power Usage

Thanks to the Victron SmartSolar Charger it’s possible to measure our actual power usage, if:

  1. We don’t use any other charge source (alternator, shore).
  2. There is more solar than we need.

When both conditions above are fulfilled, we can then say that our harvest = our usage. Here is what we measured from June 25th 2018 to July 24th 2018:

Measured-Daily-Power-Consumption-VanLife-(Summer Time)

The data was gathered when we did not use our inverter at all*, so our actual power usage for the 12V DC loads is very close to what we calculated in Part B.

*At that time, our inverter was still hooked to the van battery. Since then we updated our system, so our inverter is now connected to the house battery (exactly like our wiring diagram).

11.2- Summer VS Winter Solar Harvest

Because there’s not enough solar during winter and that we can’t measure the power provided by our Sterling B2B charger (which is our main charge source in winter), we can’t deduct our exact power usage. But we can still gather and manipulate data 🙂

In the graph below, we superposed our solar harvest (harvest, not usage) during summer and winter:

Daily Solar Input, Summer VS Winter, Van Solar Power

No surprise here: winter harvest is way, way lower than summer. Note that during summer, the harvest stops when the battery is full; so we could have actually harvest even more.

What’s the point? We’re glad we installed a Sterling Power B2B (faroutride.com/b2b-review) to charge from the alternator! The Sterling is our Plan B in summer, Plan A in winter. We think the combination of solar + alternator makes a nice and balanced electrical system. It’s nice not relying on a single charge source.

12- If We Had To Start Over

Indeed, the actual wiring diagram as you know it is the result of 2 years of full-time testing, so it doesn’t get any better than this. Because our mission is to stay up-to-date with the latest and greatest products, we update our system periodically. For example, here are a few upgrades we performed over the years:

  • Upgrade our PWM solar charger to MPPT Victron Smart Solar Charger.
  • Delete the option to power our loads directly from the van battery (we never used that and it made our system wayyyyy overcomplicated).
  • Install the Sterling Power B2B instead of the inverter+battery charger combo.
  • Install Lithium (LiFePO4) Battle Born Batteries instead of our AGM battery.
  • Upgrade our monitor for the Simarine Pico. Note that we still recommend the Victron Monitor as baseline (Get the Simarine Pico if you want something high-end with advanced features).

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about us

Nice To Meet You.

Hello! We’re Isabelle and Antoine 🙂 In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. We’ve been on the road since then and every day is an opportunity for a new adventure; we’re chasing our dreams and hopefully it inspires others to do the same!

482 thoughts on “DIY Van Electrical Guide: Build Your Knowledge”

  1. Thanks for all the great information. I just downloaded your complete package. My question concerns the connections from the Pos and Neg bus bars with the battery and the Neg Bus bar to the ground with 2/O AWG. I am currently planning a very basic build with a 25amp B2B charger as the prime charging source (others to add later), a 100Ah Li battery, a few DC circuits ~45 Amp fuses total 4 circuits, and a small inverter. At 4-7 feet 2-ga should be good for 250-300 amps, why the need for 2/O for Bus Bars – Battery – Ground circuits? And with a 250Amp Terminal fuse block on the Pos side.

    Once I am approved, I will be asking these in your Facebook group. Looking forward to it.

    Reply
  2. I just came here to say thank you so much for this write up, this is fantastic and I can’t wait for updates and more info in the next few months when I will start my conversion project. You are such an inspiration and so detailed in your explanations.

    Reply
  3. Hi,

    I am almost done my wiring diagram but I have 2 questions left. In your wiring diagram in the “Main” section where the negative bus bar is I notices you have a 4 AWG wire going to the ground symbol (Is this connected to the chassis ground and is 4 AWG sufficient wire size for your system?)

    Also, from the negative bus bar you have a black 8 AWG wire going to the “120V AC” section and connecting to a ground there. I was wondering what this wire was for and how you came to sizing it at 8 AWG?

    Thank you!

    Reply
  4. Question: In Section 12 – you state “Delete the option to power our loads directly from the van battery (we never used that and it made our system wayyyyy overcomplicated).” Does the current diagram reflect that change? Thank you.

    Reply
  5. Hi – I just purchased your wiring diagram and need a component recommendation . I want to put in a switch/breaker between my solar panels and charge controller. I have two 100W solar panels wired in parallel. The manufacturer’s recommended fuse size to go between the panels and controller is 15A. I am using the same Blue Sea breakers you used, however the lowest amperage rating for them is 25A – too high for my 2 panels. Do you have an alternative recommendation?

    Thanks a bunch, stay safe – Diedre

    Reply
    • Personally I’d stay away from it as it has too many limitations:

    • Maximum alternator charging current: 25A
      Maximum solar charging current: 25A
      Maximum solar voltage: 25V (so if using multiple panels, series connection is not possible)
    • Reply
  6. Hi my 1st van built – now planing and manifesting – best comprehensive write up on net with information’s and choices to meet your budget/ requirement – question 1- on -ve busbar one line AWG4 /15 ft is seen as see tutorial – where can i find explanation? – question 2 – once i download your wiring diagram can i change components to higher or lower requirements ? also with that will the gauges of wires as well circuit breaker and fuse amp change ? thanks

    Reply
  7. Bonjour Antoine!
    I am a newbie at van conversion, and just finished the (major) outside fixes – mechanical, body , roof , etc.
    I’m moving to the inside, and planning the electrical , as I’m doing insulation, floor etc.
    Your site has been soooo helpful. I plan to use many of your links to buy stuff – once I know a bit more what to buy.
    Mine (elect) will be a bit simpler than yours: 1. shore 2. Solar (later) . No plan for alternator (Sprinter van… and no plan to live in it – just skiing, biking, surfing, windsurfing… California living!)
    So, at the core of the electrical system is the battery, and based largely on your comments, I’ll go with LiFePo.
    But what do you think NOW about BattleBorn? The Relion that you showcase (specs all available) is now $$ cheaper. Amazon has a few other interesting options too: Lynx has a 120Ahr with Daly BMS for less than $700… There’s even a 200Ahr “AmpereTime” with BMS for $1300. Am leaning on the Relion because I see the specs – still nothing from BattleBorn??. what’s your current analysis a year or so after your upgrade?
    Time for a battery update? Things change fast. Please post a link to your “new” choices, if you care. it’s a big big expense (btw, the Trojan link is not very good – no one carries that. Use Amazon, it’s COVID time! 😉
    Merci beaucoup- j’ai hâte de voir l’analyse.
    Pat

    Reply
  8. Hello,

    Many thanks for sharing your experience and tons of tricks and engineering effort! I’m building my setup with the battleborn battery (LiFePO4) ; I’m finding conflict information out-there on the web that the SEC1230UL or SEC1250UL charger is compatible? Are you using it with those? (and only 2 stage charging set since 12V loads are permanently connected?)

    Many thanks!
    Max

    Reply
  9. Hello, I am new to conversions and looking to do our first one in a year or two. I am doing a lot of research and love your site and have recently purchased your guides! In reading around the internet I have seen quite a bit of talk about using a 24V system instead of a 12V system. I didn’t see you mention 24V systems at all in your article and wanted to ask why you didn’t mention it.

    Reply
    • Ack sorry, I just saw the “older comments” button and saw your response to the 24V question. A follow up then would be, from the forums I read, and the products that were linked, many common 12V appliances support 24V. The examples were fridges, freezers, and even the Espar heaters. If one could find the appliances, would it make sense then to go the 24V route?

      Reply
  10. Merci pour toute l’info Antoine.

    J’ai cependant une question au niveau de ton BlueSea Master Disconnect Switch.

    Avec l’utilisation d’un Bus Bar, était donné que plusieurs sources sont connectées au Bus Bar, autant positif que négatif, advenant qu’on voudrait couper complètement le courant dans la van, en plaçant la switch à “OFF”, ça n’isolera que les batteries. Les autres composants offrant du courant (panneaux, alternateur, shore…) fourniront quand même du courant 12-14v qui pourra être consommé sans les batteries, ce qui pourrait ne pas être souhaitable dans le cas où on veut vraiment éviter du 12v aux appareils.

    Ceci implique que techniquement pour tout bien isoler, non seulement le main devra être à “OFF” mais aussi les breakers devront être manuellement fermés.

    Est-ce que ma compréhension de ton diagramme est adéquate?

    J’ai aussi vu un système à double Bus Bar positif avec un second “main” entre les deux, pour isoler les apports et les loads. As-tu considéré ce design où est-ce que tu te fies que les 2 breakers (12v fuse box + samlex inverter) seraient simplement fermés manuellement au besoin?

    Merci!

    Reply
    • En effet, pour isoler complètement les loads if faut fermer la switch ET les breakers. Il serait possible d’en faire autrement si souhaité, mais en ce qui nous concerne ce design nous convient!

      Antoine

      Reply
  11. Hi
    These Covid 19 restrictions, like not being able to cross international boundaries have led to more thought and creativity regarding your electrical diagrams. Nice touch on the interactive video. I downloaded the new diagram to replace the one we purchased. I have a few questions: I don’t see the ground going from battery/chassis ground to the Sterling. Is this an oversight or did you find that it was sufficient have output negative to busbar only? (That would be sweet). The only negatives on your shunt are the battery and negative bus bar and not the charge sources. The inverter, Sterling, shore power and solar charger are connected to the negative busbar. So does the Victron 712 register the charge and discharge from these sources.
    Muchas gracias
    Pooh

    Reply
    • Not an oversight, that’s how it is connected.
      The negative of the charge sources are connected to the negative bus bar, so they are all taken into account by the Victron 712. The Victron monitor output the total balance (charge – draw).

      Cheers

      Reply
  12. What a wealth of knowledge! Thanks.
    A question on cycle life of the battery. You suggest that in general we cycle once a day in a van with solar. If we were only consuming 20-30% of our battery per day, and so disconnected the charge source for 3 days at a time – could that essentially reduce the charge cycles, and hence lengthen the battery life?

    Reply
    • I wouldn’t do that. Yeah that’s less cycle in theory, but you’ll get deeper DOD which is not economically advantageous in term of life cycle (especially for lead acid battery).

      Reply

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