The Sterling Power BB1260 Battery to Battery (B2B) Charger play a major role in keeping our camper van electrical system balanced and healthy. How’s that? The B2B charger uses the van alternator power to charge our house (auxiliary) battery while we drive. It’s an install-and-forget device: it turns itself ON/OFF automatically when driving the van, doing its things without user intervention. Neat! It means that we don’t have to worry about running out of power AND that the house battery lifespan is maximized. Sounds too good? Keep reading this review as we get into more details…


Sterling Power B2B in Van

Vanlife Essentials!


How does it work?

The Sterling Power Battery to Battery charger is installed “between” the van battery and the house battery (more installation details further in this article). There is no switch or button to initiate the charge! You see, when you start your vehicle the alternator kicks-in and raise the voltage of the van battery in order to charge it. The B2B senses the higher voltage and turns itself ON automatically. Now when you turn your vehicle OFF, the alternator stops and the voltage of the van battery drops; the B2B senses the dropped voltage and turns itself OFF. All of that happens without user intervention (well, except the part where you drive your vehicle!).


Why is it beneficial to the house battery lifespan?

Each type of battery (Gel, AGM, Lithium, etc.) has a specific charge voltage; with an isolator or an ACR (instead of a B2B), the house battery receive a “random” voltage (same as the van battery). You probably heard of battery’s memory effect, right? It’s real! If a battery doesn’t get a proper multi-stage charge (bulk, absorption, float), it looses its total capacity and that’s non-reversible (knowledge is power: we recommend reading the Charging Profile section of our Electrical System page to really understand what that means). Bad charge = wasted money (the battery has to be replaced more often), so we think the B2B charger pretty much pays for itself in the long run.


Are solar power AND alternator power (B2B) both needed?

Solar Panels Installation

Here’s what we think about that:

  • If you live full time in your van, we say a B2B charger is 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 as solar can provide the bulk + absorption charge on its own.
  • 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. Sun angle is too low, solar day is too short and overcast weather is more common (for USA and Canada at least).


What we Like…

  • Surprisingly easy to install (scroll down for installation write-up)
  • Install-and-Forget!
  • Fast Charge (up to 60A during the bulk charge)
  • Provides a nice multi-stage charge that keeps the battery (Gel, AGM, Lithium, etc.) healthy in the long run


What we Don’t Like …

  • The internal cooling fan is quite noisy; think of a tiny hair dryer. If possible, install the Sterling charger further back away from driver / passenger seats to minimize the noise.


Models & Where to Buy

There are a few variants of the Sterling Power Battery to Battery charger, so make sure to select the appropriate one according to:

  1. Input voltage (most likely 12V…)
  2. Output voltage (most likely 12V…)
  3. Charge current (30A or 60A).

It basically comes down to either BB1230 (12V input, 12V output, 30A) or BB1260 (12V input, 12V output, 60A) model. We highly recommend the BB1260 for a faster charge (so a short drive goes a long way 🙂 ), unless of course 60A is over the maximum current recommended for your battery.

Sterling B2B 1230

Sterling Power BB1230 B2B Charger. Buy from Amazon.

Sterling B2B 1260

Sterling Power BB1260 B2B Charger. Buy from Amazon.


OK there’s actually another model, the Sterling Power BBW12120 which has 120A output (12V):

Sterling Power BBW12120 B2B

Sterling Power BBW12120 B2B Charger. Buy from Amazon.

But before selecting that model, please consider the following:

  1. Batteries generally have recommended and maximum charge current. Going overboard is a waste of space (this charger is bigger) and money.
    • Check your battery manual or data sheet to find out.
  2. Make sure your alternator can handle that much current so that you’re not draining your van battery.
    • For example there are two alternator options on the Ford Transit: basic (150A) and Heavy-Duty (230A). It is believed (not official info) the Transit needs roughly 70A for itself (lights, radio, etc.), so we’re left with 80A extra current with the basic alternator and 160A extra current with the Heavy-Duty alternator. If you have the basic 150A alternator (80A extra current) and you’re charging your house battery at 120A, it probably means your are “borrowing” that extra power from the van battery…
  3. Overworking an alternator might reduce its lifespan.


Installing the Sterling BB1260 B2B Charger

First of all, as always, make sure to read the manual (choose the latest version). The manufacturer knows his product better than anyone else.



Make sure to install the B2B charger into a well vented space and do not obstruct the hot air exhaust:



Wiring and Electrical

It’s honestly quite simple. Here are the required connections:

  1. Positive Input (From vehicle battery)
  2. Positive Output (To house battery)
  3. Negative (Common to vehicle and house battery)
  4. Temperature sensor (To house battery negative post. Optional, but recommended. This is to correct the voltage according to temperature change)



For safety sake, remember to add fuses (or breakers) on the positive wires and to select the right wire diameter according to length / fuses. Not sure why or how? In this case, make sure to read our electrical system guide! We first start with the theory (so you understand what’s going on), then YOU do the work using our Interactive Diagram and our Tutorial:

Electrical System: Build Guide for DIY Camper Van Conversion

Here is a sneak peak of what you will find inside the article:

Wiring Diagram


From-Blank-to-Wiring-Diagram-Animated-GIF (V2, rev A)



Default Options

Here are the factory options for the Sterling BB1260 Charger:

  • MODE: 1
    • (Mode 2 is identical to mode 1, except it needs a live signal on the ignition feed input in order to charge)
  • ACTIVATION VOLTAGE: vehicle battery above 13.2v (for 5 seconds)
  • TURN-OFF VOLTAGE: vehicle battery below 13.2V
  • TURN-OFF TIMER: 240 seconds
    • (A timer is required to complement the regenerative braking aspect of modern Euro 5 / 6 + engines – where the alternator’s voltage can drop below 13V for a short period of time)
    • Because our Ford Transit 2016 does not have regenerative braking, we changed the turn-off timer to 30 seconds (procedure in manual). This is the prevent draining the van battery, especially when running errands (multiple short drives).


First Time Use

The unit will enter “config” mode at first startup; this is your opportunity to change the charging profile according to your battery type.

  • The configuration can be changed later, check the manual.
  • To find out which charging profile to select, check your battery manual.


First Time Use Configuration Sequence:

  1. To initiate the first startup, turn on the vehicle and wait a few seconds. To indicate the B2B has turned ON, LEDs will light up, a beep will sound and the fan will run for 5 seconds. If none of that happens, try to “force-start” the unit: simply press and hold SETUP/ENTER for 5-9 seconds.
  2. At this point, a LED is flashing to indicate the battery type (default = lead acid).
  3. To change the battery type, press and hold SETUP/ENTER buttons for 10-12 seconds (up to 20 seconds); all LEDs are now flashing.
  4. Scroll down (SELECT button) or up (ENTER button) to select your battery type; Press and hold SETUP/ENTER buttons for 2-3 seconds to confirm the selection.
  5. At this point, the B2B charger will restart.
  6. If you have a battery monitor, such as the Victron (, you can observe that the B2B is charging the house battery…
  7. That’s it! Go for a ride!


To change the configuration later or for advanced options, check the manual.



Once the installation and initial setup completed, just drive and let the Sterling Power B2B charger do its thing!



We installed the Sterling Power BB1260 B2B Charger in October 2018; so far so good! We will keep you updated if anything happens! Subscribe to our Mailing List to be notified.






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  1. Comment by Brian J

    Brian J Reply November 27, 2018 at 10:31 am

    Nice work guys! We installed this in our Promaster back in December, going great since then!

    • Comment by Antoine

      Antoine Reply November 27, 2018 at 2:43 pm

      Good to hear!!

  2. Comment by Jay

    Jay Reply November 14, 2018 at 12:24 pm

    Will the B2B charger overload the alternator for a fully drained house battery? 60A is a lot.

    • Comment by Antoine

      Antoine Reply November 15, 2018 at 10:50 am

      It totally depends on your vehicle / alternator.

      For example there are two alternator options on the Ford Transit: basic (150A) and Heavy-Duty (230A). It is believed (not official info) the Transit needs roughly 70A for itself (lights, radio, etc.), so we’re left with 80A extra current with the basic alternator and 160A extra current with the Heavy-Duty alternator.

      Don’t know about other vehicles!

  3. Comment by Interstate Blog

    Interstate Blog Reply November 11, 2018 at 9:30 am

    I caution against over-reliance on the Sterling. There’s a general perception in the off-grid van world that the Sterling is all that is needed to be protective of the alternator, but there’s also evidence suggesting that it is only protective in SOME ways, not in all ways.

    My husband and I upgraded our Sprinter-based off-grid van to a 200 A Bosch alternator and installed a Sterling between it and our house battery. Within 17 months, the alternator clutch pulley failed on what should have been a viable set-up. I researched it, and found plenty of other stories on the internet about these alternators failing under high-demand scenarios when they are not supposed to.

    The safest way to incorporate alternator charging is with a second engine alternator. If you use only one alternator, I would advise a real-time voltage monitoring and alarm system for your chassis battery because if the alternator begins to fail, that’s where it will be reflected first. You don’t want to find yourself stopped dead in the middle of an interstate highway, and that’s what will happen if you don’t catch the failure in time. That’s what ALMOST happened to me in the middle of rural Mississippi this past August. Fortunately I had an OBD and noticed my chassis battery dying in real time, such that I was able to intervene.

    • Comment by Antoine

      Antoine Reply November 11, 2018 at 9:41 am

      Sorry to hear that…
      On our Transit, we went with the Heavy-Duty alternator option (230A) and hopefully it’s up to the task! I’m still lurking on the Transit forum and haven’t heard of people having issue with the Transit alternator.

      Thanks for your input!

  4. Comment by David Richards

    David Richards Reply November 10, 2018 at 9:56 pm

    Great article on a great solution! At the time I installed our BB1260 back in March of 2017 the LiFePO4 setting had no setting to shut down the charger when fully charged. I was forced to allow a floating charge. LiFePO4 batteries are not supposed to be float charged. I set the float charge voltage to the ambient voltage of my battery bank (around 3.2V per cell, as I recall) hoping that the current would be negligable. If Sterling still forces a float charge, how are you dealing with the float issue?

    • Comment by Antoine

      Antoine Reply November 11, 2018 at 9:44 am

      Hi David,
      I found that on the BattleBorn Batteries website: “A float is unnecessary, since Li-ion batteries do not leak charge, but a floating voltage under 13.6V is fine.”

      Check with your battery manufacturer to see if that applies too. I’m guessing it’s fine!


  5. Comment by MedicineMan

    MedicineMan Reply November 10, 2018 at 8:00 pm

    Another great review.
    We switched to a Sterling-Power BB1230 (30 amp model) after switching to Battle Born lithums 6-7 months ago. So far performs a champ!
    We did not go the ‘automatic’ route though. Since going lithium I’m more ‘hands on’ and keep an eye to the smartphone app and the Victron battery monitor and decided when to flip a switch turning on either solar charging or B2B charging via the Sterling model.
    Since switching to lithium our reserve capacity is so much more than we had with lead-acid that we can go extended periods of time before needing any Sun or having to B2B or find a pedestal (we hate pedestals!).
    So far we’ve not noticed the fan noise, but the 30 amp model might be quieter?

  6. Comment by Aaron

    Aaron Reply November 10, 2018 at 4:09 pm

    Make sure that you don’t accidentally put it in standby during setup. We did and didn’t diligently check it until our big month long trip because the battery was always full. Then after days and days of rain our battery voltage level crashed in the middle of the night which caused our propane detector to turn on and off beeping to wake us up. (I assume this was because the current draw of the detector would lower the voltage and then turn off the detector, then with the detector off the voltage came up to turn the detector back on). Anyways it was a rude awakening on one of our Walmart nights. After trouble shooting a bit I realized that during the setup steps I did too many button pushes and put the unit in standby. As a result we were never getting a charge from the alternator.
    Beside that I like the Sterling paired up with our Battle Born Lifpo4 battery.

  7. Comment by Stéphane Lavergne

    Stéphane Lavergne Reply November 10, 2018 at 3:04 pm

    Don’t forget about its more powerful cousin, the BBW12120. It’s what I’ll be using to charge my 600Ah beast of a lithium battery. 🙂

    • Comment by Antoine

      Antoine Reply November 10, 2018 at 3:50 pm

      Woah, induction cooktop I’m guessing?

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