I Added a 10KW Battery Array to My Trailer

[@meilyn22]

Don't know how to tell you how good this video was! That diagram and explanation is everything.

[@jonlawrence]

Thank you, I really appreciate that!

[@fredberghoff9917]

Excellent work!! Thank you very much for that super nice wiring diagram! Happy Trails!

[@WattsinWattsout]

Very clean job.

[@ThreeDayRV]

Nice work, we did ours similarly and love the freedom for boondocking. Subing!

[@junkerzn7312]

You did quite a few things right. Actually you almost got everything right, kudos! The only real mistake you made was putting two 12V batteries in series and then paralleling two sets, instead of putting 4 x 24V batteries in parallel. Since you have 12V in series, make sure you have a whole battery balancer. You'll need two of them, one for each set of two. Otherwise in a few months the two 12V batteries will get out of balance between each other and things will get wonky. NOTE: the leads must have inline fuses. ALL wiring on the batteries, even if only sensing and balancing cables, need fuses. I recommend inline glass fuses. Going with a 48V system voltage would have been even better given the size of the solar arrays, but it isn't the end of the world. 24V as a system voltage is already heads and tails better than using 12V as a system voltage. A couple of checklist items: * Those "lever" breakers are horrible. They generally aren't real breakers so you may want to consider replacing them with DC MCBs (miniaturize circuit breakers). However, make sure that you get 2-pole breakers and that they are NON polarized breakers. * Break both poles, always. Both the plus and the minus. * Whether 2-pole or not, whether polarized or not, any breakers with a wired connection to the battery should have the battery on the LINE side of the breaker. Even if the current direction (such as breakers related to charging) is the opposite. Well, getting non-polarized breakers is the main thing. But to be absolutely sure since it is hard to tell, the battery should be on the LINE side of the breaker. The reason is that the battery is the highest-current / shorting-danger that the breakers might need to break the ARC on. Charge controllers are current limited. * Always fuse the solar panels according to the solar panel specification. A 30A fuse is probably way too high on the solar panel side. The specification will say what the maximum series fuse value is. * Put a plastic separator between your two bus bars. They are way too close together. * Make sure your tools are insulated. * Venting. That bay where you have the batteries and equipment needs to have a direct vent to the outside, and preferably fans. Make sure you have a mesh on the outside to prevent insect / critter ingress. Fans should exhaust directly to the outside for safety... if a battery failure occurs you don't want the fans pushing toxic white smoke into the trailer. The intake side can also go to the outside of the trailer. Make the fans temperature controller but also with a way to turn them on manually. * Safety. Have a smoke alarm in the bay, and in the event of a battery failure. * Weight issues. If you want to add more batteries in the future, consider putting the additional batteries on the other side of the trailer to improve the weight balance. You already have quite a bit of weight in that bay. Don't worry too much about making the cable lengths perfect for crossing cabling, it isn't that big of a deal since any expansion you do will reduce the cycling of the entire battery system considerably, trumping any mismatched wear that occurs due to the currents not all matching. LIFEPO4 BATTERY FAILURE / SAFETY * LiFePO4 is a very safe lithium chemistry, but thermal runaway is still possible. Usually it just results in a lot of toxic white smoke and no fire, but that isn't guaranteed. The problem is the toxic white smoke, so make sure you have the proper detector in there and fans that exhaust to the outside. * Generally speaking, lithium battery runaways cannot be put out so basically you are left there hoping that they don't cause an actual fire. Having fans to exhaust the toxic smoke to the outside is a good idea (temperature controlled fan directly connected to the battery with only an inline glass fuse, so it runs even if all the breakers are open). * Consider rearranging the bay so the batteries can be directly accessed from the outside and ripped out by main force if necessary. Putting the batteries on Anderson quick disconnects helps there (usually in sets of two). -Matt

[@junkerzn7312]

I'll add a bit more about inverters and external power. Typically in a system this big you will want to have at least two inverters and maybe even three. Remember that the size of the invert correlates with the vampire power it draws. A small inverter might eat 5-10W, a mid-sized 10-20W, and a large inverter might eat more power just by being on. Make one inverter small and use it to run basic low-power equipment in the RV, such as lights, computer, internet, etc. This gives you the option of simply leaving this inverter on 24x7 or nearly 24x7 without having to worry about the vampire power draw eating the batteries up. This inverter could also power a fridge, for example. Make the other inverter(s) larger for power large appliances. A/C, induction tea kettle, induction burner (stovetop), toaster oven, micro-wave. One or two large inverters. The key for these inverters is to get inverters with a remote switch input and wire the switches into the kitchen area of the trailer. That way these larger inverters can be turned off when not in use and thus not draw any vampire power. AC appliances are fine for things that don't use a whole lot of power. That includes the fridge. DC appliances are great if you want power efficiency, but the problem with DC appliances is that you have to match them to the system voltage (24V in your case), which reduces your flexibility later on if you want to change the system voltage to 48V. So be aware of that when buying big appliances. -- For shore power, consider removing the transfer switch and just having everything powered from the inverters. Instead, have the shore power connection go to a battery charger. I'll use a simple example... say, a Victron Energy Blue Smart IP67 24-Volt 12A battery charger. Something like that, though presumably something that can do more amps. That particular charger can only push about 300W into the system. The reason is that you have enough energy storage that you do not need to risk bad shore power blowing up your trailer's electronics. Ultimately the amount of charging capability you want will depend on comfort and convenience. For example, if you have an A/C system or electric heater you would probably want enough shore charging capability to run the higher of the two plus a bit extra. At the same time, having a small charger is useful too, when visiting friends, as you would only need to run a 120VAC extension cord. Well, no reason why you couldn't have multiple chargers in the system! -Matt

[@jonlawrence]

Thanks for your remarks

[@TheSmallsRVAdventures]

Wow. That’s a lot of power.

[@marioluna4344]

Thanks for the video create info and diagram. What’s the length of your Rv? I have a similar looking Rv (27ft) to your and I want to be able to put that many solar panels as well.

[@jonlawrence]

You nailed it exactly, 27 feet.

[@tystevenson8185]

Great video bud. What program did you use for your diagram?

[@jonlawrence]

Thank you! Figma is the software I used for the diagram.

[@qux8508]

Nice video! you might want to to 48v instead of 12v? What software do you use to make those diagrams?

[@jonlawrence]

A little late for 48v, but I went 24v for a specific reason. I used Figma to make the diagrams.

[@tomstdenis]

Looks like a good DIY install. Only comment is your panels should have some form of rapid shutdown (like TIGO devices) and the system should have an E-stop button (ideally on the inside and outside of the camper).

[@jonlawrence]

Thanks

[@te0nani]

Long therm, a balancer to keep the voltage equal between the two batteries in series would make sense.

[@jonlawrence]

You are right, I added a balancer to the batteries.

[@craftyoldman]

Where did you get the switch?

[@jonlawrence]

a.co/d/4kg1LIA

[@ghostflight73]

Think you have enough power? :-) Nice job can boon dock forever. Enjoy Nice seeing pride in workmanship. Lost art anymore.

[@jonlawrence]

Thanks 👍

[@quickquote1568]

Why on Earth did you choose that cheap high frequency, transformerless inverter with its short life expectancy, and poor surge capacity? For a little extra money you could have purchased a far more reliable, longer lasting hybrid, low frequency, transformer based inverter charger that would have provided you with a much higher surge capacity and a much safer source of power.

[@jonlawrence]

Sorry to disappoint you

[@WattsinWattsout]

@@jonlawrencethis is something that can be upgraded later, no problem. Last year I bought a 24v 5000w, now I have 4 inverters. Not to worry, there are still affordable HF inverters that last many years. CNSWIPOWER and WZRELB have decent histories for longevity. Renogy also has them but they are a little more costly.

[@ThreeDayRV]

@@jonlawrence if you're like me, I hit the budget wall and knowingly will get a better inverter down the road. As long as your are enjoying it all, well then Great Job! Upgrades can easily come down the road. High 5 man, nice work.

[@ve4edj]

What's with all these comments bashing transformerless inverters the past month? I've been seeing them everywhere all of a sudden... Coincidence?

[@LLampen]

Looks like a 10 kWh battery setup. There is no such thing as a 10KW battery, also you do not have "200 Amp batteries" as said in the video, those are Ah (Amp hours)... Watts equal power at any given moment, and kWh tells you about the capacity, as well as Watt hours do. Upper case K is Kelvin and small k is kilo. Nice video and ideas anyhow, keep it up. 👍

[@jonlawrence]

Thank you for the correction