Red's electric apu thread

Just swapped them out. The Northstars have about 20% more capacity and built to tolerate more deep cycling. That's the simple answer, but there's some thought behind it.

That's the problem I ran into when researching this stuff and figuring out what's what. Reading internet posts from others, power solutions are all over the place. What nearly nobody does is explain why they did it that way, nor do they ever report what didn't work out. For example, I read 100's of posts/articles and not one single person mentioned the problem I ran into with the large adhesive solar panels.

Back to the batteries: using my best estimates, I figured I could run with the hvac only on truck batteries with some limited idling to begin with, then re-assess once I had some actual use data and go from there. I already had the batteries out of a truck I traded, so I wasn't just running out and getting a $1500 set of primo batteries on a whim. They were already there in the garage, so why not? I'm already re-using the still good Mack batteries in my reefer units.

I'm on the fence with the second truck, for now. For the price of another set of new Northstars, I could buy a pair of 200 Ah LiFePO4 house batteries, then a little extra for an isolator to charge them off the truck alternator plus the solar I already have. That would be more ideal, at the expense of another install and wiring project. On the other hand, that truck is now coming up on 2 years old and the Mack batteries are getting some age and showing signs of reduced capacity from ordinary use. Going to be time to replace them anyway. Getting solar installed on that one with fresh Northstar batteries will get the job done without adding much install overhead. I don't need to solve that today, so I haven't.

This leads me to a secondary consideration: how long I plan to keep the truck and how much time and money to spend on all this crap. I got these trucks on a 5 year deal, expecting to trade before mid-life repairs started mounting up. I could buy them at the end instead, but would really need to consider that carefully. The older truck has another 3 years before that decision point, which leans me toward just replacing the truck batteries with better. No need to spend more on a greater solution if it's just going to benefit the next owner. When these trucks sell, I'm not taking anything out. The mini splits are pretty much permanent, and the rest not much value compared to newer stuff on the market for the next one.

That in mind, I'll have a more solid plan with the next new truck cycle, and have a more complete system from the get-go. If I did a do-over right now, I'd do the following:

• Install the same mini split
• Run it off 400 Ah of LiFePO4 house batteries on an isolator and solar
• Swap the main bunk power supply over to the house batteries so overnight bunk heater and refrigerator loads are off of the truck batteries.
• Same or more solar capacity with more smaller panels for a cleaner install.

I believe that would be ideal to suit my use pattern: 3-4 overnight breaks in the truck plus dock time. Someone that routinely stays out weeks at a time might want more house capacity, if they aren't checking into a motel to stretch out during a reset. Someone that runs mostly local and doesn't overnight in the truck often could probably get by just upgrading the truck batteries.

 

Check out Hobotech videos on YouTube. He's done some conventional glass panel installs attaching them with VHB and/or Endurabond. Those panels are more efficient, the install provides the air gap, and they're just as durable. Probably way easier to replace if one did happen to get damaged or fail. Dice1, who used to be on here, has done that on his older condo Volvo, right over the top of some 10 year old adesive panels. He's also installed an elaborate house battery system. He's on the 9+mpg FB group if you want to have a look. With a mid roof, you'd have zero issues with clearance. None of these folks have reported wind noise problems. I suppose it wouldn't be too much more to rig up an air deflector of some sort if that turned out to be a problem.

 

I am currently running only on the truck battery set. LiFePO4 batteries are no bueno for engine start, so for now it's premium hybrid gel batteries. If I did house batteries, I'd definitely go with LiFePO4 for those reasons. With that, the only remaining justification for the better truck batteries would be longevity. I ran another set of these X2Power batteries in my old T600 for 4 years then I traded it. No other battery lasted more than 26 months.

 

I considered putting them on the trailer, but opted not to be dependent on that. You'd either need an aux power cord and sockets to run it all that time, or connect a patch cord when parked and try to remember to stow it when you go. Being that high up increases the risk of tree branch strikes too. You'll have 10 AWG double insulated wires (maybe 1/4" dia plus any conduit and mounts) connecting the panels to each other then down - those stick up a little bit too. I don't carry my extension ladder on the road, so if they got tore up by a tree they'd stay tore up till I got home.

Now I do know a guy that uses a patch cord to his reefer unit to power a mini-split, then sets continuous run overnight. He says it works great. I wasn't keen on that, given the factory TK alternator is only 37A and a pain to swap when it dies prematurely (S-700), not to mention $300 a while back probably more now. I know they sell higher amp ones, but I'll put a bigger one on the truck before I ever do that.

 

I ran across one or two "shrinkwrap" systems and didn't bother. You just about have to be Sherlock Holmes to figure out just exactly who makes it, then you can only contact, and must purchase it and have it installed by only one authorized dealer and installer that's never within 1,000 miles of you and somewhere you never go. Usually with features you don't need jacking up the cost. And of course the price is always listed as "call for a quote."

That said, these "kits" are usually some kind of compromise. There's such a huge range of use cases in trucking that a one size fits all solution usually isn't.

Both are the reason I went with the Rich Solar kit. Maybe the components aren't the very best or very cheapest. What I did observe is that they do have a physical store, and the components appeared to be decently matched and of adequate quality (which they actually were). They also used standard wiring terminals and even offer them for sale in case you want to cut custom lengths.. I did that and have plenty for when I make any changes to my install. My fitment issues with the large adhesive panels are all me, not knowing what I didn't know, and not getting any critical internet clues during the shopping process. I'll buy from them again, until I see some equivalent products at an equally legit retailer closer to me.

I never go west of I-35, so I won't be visiting their store in LA unless I happen to be out there on a once in a decade family visit and have time.

I'll also add that it takes some time to digest how these solar systems work, and become knowledgeable enough to make better choices. Many cases where I saw the same thing about 4-5 different ways before the sun rose over marblehead and I got it.