Battery powered rooftop AC installed in my sleeper.

I have the same one going in a flattop Peterbilt 379 running the same exact batteries, have a renogy dc to dc charger though otherwise same setup, glad to hear it works, I also have a solar panel for my cab roof but probably am going to use that for a roof top tent on my 4 runner

 

Even if you don't do solar, look to those guys for ideas on power management and parts. The ones that run separate house batteries are buying the LiFePO (Lithium Iron Phosphate) batteries. 1/2 the weight of lead/acid, you can discharge them all the way to zero without harm, and they hold adequate voltage right up to the end. They just aren't suitable for starting, so not good for an all-in-one plan. And kind of expensive, but they are becoming more affordable.

I'm running a mini-split on mine and see similar charge times after an overnight. However, daytime use is not ideal. I haul a reefer, so that's needed. I'm using the truck batteries, but have swapped in a set of Northstar hybrid AGM batteries good for about 25% more capacity over the standard AGM's the truck came with. I've got 480W of solar to go on the roof, just not enough time to get it done yet. My goal is to offset heavier demand during the daytime, to preserve more capacity for running the a/c overnight. Also, the solar panels will charge all day even with the truck running. So will supplement the factory 135A alternator and likely reduce recharge time when driving in daylight. I've considered building or buying a beefier alternator, but going to see how well the solar performs before doing that.

ETA: Nice job on the insulation. I don't know what I was thinking, not going to home depot for some of that when I had my back wall peeled out for the mini install. May not have been complete, but you're not kidding about the pretend insulation used by the factory.

 

I don't know where you priced your batteries, but 200Ah LiFePO are on Amazon all day for around $700-800. 100Ah for half that. And you don't have to stop at half discharged, use all those sweet amp-hours to stay cool longer. LiFePO can be installed safely inside, no gassing. In fact, they usually are installed inside to avoid outside temp extremes. Definitely a superior solution for house power. I'm going into this a piece at a time, staying behind my skis cash flow wise for now. I know I'll regret not going all-in like everything else I've gotten into, but I also don't live in my truck either. I do 3-5 day trips, so my use case is a bit more limited than someone that stays out weeks or months at a time. Something that works for me probably wouldn't be enough for others.

 

Thanks for being the lighthouse. Please follow up on how the new one works out.

I guess that means I better get with it on my solar panels. My truck has a 35si Delco 135A, so I won't be far behind you I'm thinking. I have a few months of warranty left, but a like replacement would only buy limited time. Boy those prices jump when you go up on output. I'm gonna do some measuring and see if a 40si will fit. 240A is about $700 and the 320A is double that. Wow LOL.

Not to hijack or anything, but today was a stress tester. Heat wave here in the southeast, and I had a delivery to complete at Walmart. The mini split did hit the batteries pretty hard, but kept it cool and comfy for the 2 hours I was there. 98º outside and it was running 600-680W constantly. Batteries were down to 11.9V when I got the "come get your bills" call. Soon as I took the load off, the voltage went back up to 12.2V. There might have been another 1/2 to 1 hr worth of battery left before I would have chickened out and started the engine.

Two times even close was a couple weeks ago - it was 92º outside, late afternoon both times, and it ran like that about 30 minutes then dropped once the cab temp stabilized. Windshield curtains were closed, so that probably had a lot to do with it. Today the curtains remained open, sort of on purpose to see what happened. I may also revisit that insulation as well.

 

Looks real nice. Glad it works out great for you.

 

For my Electric APU I had to have a
320 AMP
Alternator.

 

When I was an O/O I carried spare belts , a spare alternator , a spare tire , spare mirrors , extra triangles to toss out and if I forget to pick them up I could still pass a inspection ,

carried super heavy duty jumper cables , a heavy tow strap , wire in several different gauges and all kinds of connectors ,
I carried air line and a huge assortment of fittings connectors couplings etc , a spare brake can , mud flap , spare of every light , etc etc

even if you don’t have the skills or tools to install the spare part , it still saves lots of time and money when you have the part with you since you don’t have to pay the road service to find and fetch the part and pay their 200% price jack on the parts.