2024 Globetrotter 30 - 21.5kw battery install

[russellt]

Hey guys, I just completed a 48 Volt, 6000VA inverter install on my 2024 airstream. Total batteries are 21.5kwh and an additional 2kwh 12v.

I chose behind the fridge for the inverters as there’s tons of space now that they’ve done away with the adsorption fridges.

The batteries in the storage locker under the table which was a pain to access so hopefully won’t miss it much.

I went 48v this time, as in my last airstream I didn’t like how hot the 12v system ran.

If anyone has any questions I’d be happy to answer them asI had a bunch starting out and researching this took longer than installing it!

So far this is working great, and this runs both air conditioners just fine.

[JeffKim]

Looks great, I'd like to see a schematic if you have one. I don't know if I'd ever do this, but just curious. I've never seen a 48V system in an Airstream, I'd guess you need less beefy wire, but is there a tradeoff? Also, I'm wondering with your batteries it looks like you have both the positive and negative powering your system off the first battery. If so, this isn't balanced, or am I missing something?

[shannonc]

I'd love to see a schematic too. I'm really interested in how you're using the Blue Sea solenoids. I've thought about using those to re-purpose the Store/Use switch.

[russellt]

Originally Posted by JeffKim

Also, I'm wondering with your batteries it looks like you have both the positive and negative powering your system off the first battery. If so, this isn't balanced, or am I missing something?

Thanks for catching this. I ran out of 4/0 cable. When I hooked them up like this and ran max load, I couldn’t get a voltage difference between the front of the bank and the back, to two decimal digits. So both readings were averaging 53.61v. Maybe because the conductors are oversized?

They all discharged even too (these batteries have Bluetooth and you can check individual capacity).

Do you think it’s worth the expense of getting a longer cable?

[JeffKim]

Originally Posted by russellt

Thanks for catching this. I ran out of 4/0 cable. When I hooked them up like this and ran max load, I couldn’t get a voltage difference between the front of the bank and the back, to two decimal digits. So both readings were averaging 53.61v. Maybe because the conductors are oversized?

They all discharged even too (these batteries have Bluetooth and you can check individual capacity).

Do you think it’s worth the expense of getting a longer cable?

Yes, most definitely. Here's a thread where the OP had the same hookup for his Battleborns and after five years or so two of his five were dead. It ruined his batteries and BB wouldn't replace them. He has a great explanation and the discussion has some excellent points as well about balancing and better ways of balancing like using bus bars or half-way connections. I have ours with the standard one end to negative and the other to positive. Which from what I read is not perfect but adequate.