Possible APU alternative

Wind energy will be a lot more expensive than solar.

 

Here's the way:

4 6-volt, 100Ah batteries mounted in a box on the catwalk and wired in series/parallel to give 12v output. DC to DC charger from your chassis batteries that activates when the engine is started, allowing for the alternator to charge them while you drive. Add in a couple of those flexible solar panels on your roof... cover as much space with them as possible. If you can get 400w of panels up there, it will shorten the charge time off the alternator and maximize the available power when shut down for a 34. Use a Pure Sine Wave inverter for the A/C unit, size it 25% larger than the maximum startup draw from the A/C.

At that point, what is your cost? $800 in batteries, $100 for the box, $100 for the cabling/terminals, $200 for the DC/DC charger, $500 for the PSW inverter, $500 in solar panels, $50 for the solar charge controller... that's $2,250 before you even think about the A/C unit itself and the installation needs. How much is the Samsung unit? $1500?

I think you are underestimating the up-front expense of such a system if designed to actually work.

 

The Tiny Home & Van Life communities have already figured this out and post plenty of videos on YouTube.

Everything a truck driver does doesn't have to be only from truck drivers. Get investment info from investment experts, clothing/boots info from clothing experts, living in a small space info from RV people, etc. APUs are expensive but any alternative will have limitations or only do SOME of what an APU will do, or will be complicated & delicate requiring lots of fiddling.

 

My truck before this one was kitted like that. Battery powered A/C will last an entire 10. Saves a LOT of fuel.

 

That's where my info and idea comes from. I am connected to the Van Life folks as I happen to be the expert in the region on repair and upgrades for the old 2002-2006 T1N Model Sprinters. I get to see all their ideas and I have begun outfitting a rental RV Conversion out of a 2005 Sprinter in my spare time.

 

In the end as the owner, you should do what you deem best. Nobody can make that decision for you. I will add I would be careful about installing an APU on a 4-year-old truck. In general, though, knowing there is an APU to keep those batteries hot if I have to park the truck for 3 or 4 days. Can have a nice fridge, microwave, maybe run a TV with some games as well as staying cool in the summer and warm in the winter is something to consider. I'm not a mechanic but I have been told the only real maintenance with regard to an APU is an oil change from time to time. Over a few years, an alternator or an AC compressor at some point might have to be replaced. During my last few years on the road before I retired in 2012, I had APUs. If I was handed a set of keys and said tractor did not have an APU I would give the keys back and go find a job with a carrier that did have one. One last point. Jeez, I can't remember the year. I was stuck in Duluth Minnesota. The outside temps during the day were single digits, and at night were below zero. Thankfully my APU not only kept my batteries hot but also kept my engine warm. Yes, you can idle in those situations but I doubt you will be 100% pleased with those batteries in that type of cold.

There are positives and negatives to EVERYTHING discussed in this thread. I think it would behoove you to make sure you get good information about them with regard to what you are thinking about doing.

 

An electrical engineer here that is changing careers (that's a story for another day) but I do know of what I speak here.

Power is Amps (current) times Volts, so your 200 Amp/Hr battery stores 12V times 200 Amp/hrs of power i.e. 2400 Watt/hrs. If you use the three batteries in parallel, this gives you 7200 Watt/Hrs. So what is a Watt/Hr? It's how much power the batter can store. You could run a 7200 Watt heater for 1 hr, or a 100 watt lightbulb 720.

I think the first question that you need to ask yourself is what do you want to power and for how long? Your setup would ideally (we are going to circle back to this later) 720 Watts for 10 hrs. My TV in the bedroom draws 144 watts, my wife's hairdryer draws over 1000. A SMALL room air conditioner draws 6000. You need to add up all the things that you are going to run, for how long, hang 10% extra onto that minimum and see if this will do what you want.

You said that the inverter draws 8 amps. 8 times 12 is 96 Watts. Notice that we are not in Watt/Hrs. here. Watts are an instantaneous value. Think of Watt/hrs as the odometer on your truck, Watts as the speedometer. You can only get the same amount of power out of an inverter that you put in (it is just converted to 120 Volts AC) so that little inverter can't power ANYTHING that I listed above.

And all these numbers are ideal. Nothing in the world is Ideal. The inverter is going to lose some power in converting the power, the batteries are slowly going to fade, etc.

I'm also assuming that the battery can provide that Watts that you need (the instantaneous value.) I'm not sure if this is the case with deep cycle batteries, you need to look.

Then how are you going charge them? If you hang it of the truck's batteries, your batteries will back-feed into the truck batteries. When the truck starts, its going to be using your batteries too. If the truck batteries are dying, it will drag your batteries down too. You could put a big diode in, but that's another thing you are going to need to size.

I hope this helps, good luck.