Making my own APU

The BIG problem with the battery ones is the batteries themselves need to be replaced almost yearly. The extreme cycling (charged to almost dead to charged) really kills the battery life and burns out alternators quicker.

 

I haven't finished this project yet but I take advantage of using my reefer unit to supply power for my set-up. First thing you will need to to is obtain a high output alternator for your unit. In my case, a direct bolt-on 200A replacement. Now depending on how fancy you want to get, you can run an additional pigtail connector between your truck and trailer. or just use quick disconnect like on electric pallet or forklift. then its just a simple matter of wiring in a 2500 to 3500 watt inverter and running a small ceramic heater or an ac unit. So you don't wanna cut a hole in the back of your cab? Well depending on how handy you are you simply buy an ac unit that your inverter will carry, evacuate the gas, split the system, mount your condenser on the back of the cab just as they do with the apu, build a box for the rest of the system and plumb the output into your existing sleeper duct-work. The BIGGEST IMPROVEMENT you can make in cab comfort is INSULATION!!!! Strip the interior and either install rigid foam insulation or spray in foam insulation.

 

The new absorbed glass matt (AGM) batteries are said to be good for up to five years and most have a three year warranty. they aren't cheap but they do solve that problem...

 

There are also regulators that will shut things down so you don't kill the batteries. Supposedly they are also built into some inverters.

 

in theory they work but they are set to cut out after the point of no return. My inverter cuts out at 10.5 volts, which isnt enough to crank over a warm engine. Also say its winter, the batteries are already in a weaker state from being cold. And half way thru the night the isolator kicks out, theres 4-5 more hours your batteries are going to KEEP losing charge from several different draws (webasto stays running regardless of isolator) and also a dead/weak battery in cold weather will continue to lose its reserves because it has less resistance to freezing. A fully charged batteries resist cold temps better then a weak battery

 

I bought mine at Gander, 900......alot of money for a small gen. You can get cheaper (china) 3hun to 4hun but as the saying goes to get what you pay for. Going to test my gen at home on a window ac, see if it will go on start up. By brackit I mean something to prevent it from falling out pass door window.

I really like the idea of using your reefer......might look into that as well. Would running jumper cables from reef to a 2000 w inverter (outside) then extension cord inside work. Or would I need a fuse inbetween.

 

ALL internal combustion engines create carbon monoxide when in use. The smart thing to do is plumb the exhaust towards the rear and try to park facing the wind if possible.

 

AND get a carbon monoxide detector.

 

best insurance. i have one in my truck.

 

don't use a window unit for the truck, it won't work in your door window, the best way to go about it is a portable unit, the one that has a hose on the back and you can place that in the window with out picking up the unit, sit the portable unit on the floor in front of the seat, and a gas honda generator, bolted down so no one will steal it, make sure you get maybe over 1200 btu cause trucks don't have much insulation, maybe 1800 or so, remember if down south 110 degree's out, you want the a/c to work good