Charging electric apu batteries with generator?

I've been driving locally a couple years and have decided to get out into OTR. The company i'll be starting with (roehl) i've been told a lot of their trucks have those apu's powered by 4 deep cycle golf cart batteries that runs an air conditioner for 10 hours (supposedly) while your're taking your 10 hour break overnight. I know there are a few different systems on the market, but for the sake of the thread, let's just call it ClimaCab. Now the problem with these, as i'm sure you all know, is when you hit your 34 restart, your batteries will be dead and you'll be SOL for the remaining 20 or 30 hours. You could start the truck and idle to recharge them, but with all the 5 minute shut-offs they have now-a-days, that probably won't work too well. not to mention you have to idle the truck for a good 8 or more hours to recharge them, which takes a lot of fuel and i'm sure will be subject to a good scolding from the company.

So my question is this: Are these ClimaCab batteries wired into the same charging circuit as your starting batteries, or does the alternator have a seperate regulator for the two? I know deep cycle batteries usually require a little diferent charging procedures than their starter battery counterparts, but who knows. If all the batteries are wired into the same circuit, then after 10 hours of cooling and your climacab batteries are dead, you should be able to turn the truck's key to the ON possition (with the engine not running of course) and your starter batteries should be able to charge up the climacab batteries. If i spent a couple hundred bucks on a little 1000 watt generator, i could use that to charge up the starter batteries, which in turn would be sent to the climacab batteries via the already existing wiring. Does anybody know if that would work?

An easier approach would be to just hook the generator (along with a battery charger which i already have) right up to the climacab batteries, but i'm not sure if they're all closed up and i can even get to them. If the two battery systems are wired into seperate charging systems, then the only other way to charge them would be from the alternator with the engine idling, which as i stated before, probably isn't going to work. Does anybody have any experience with these types of battery pack apu's that can answer this?

 

as i said in the original post, if the trucks weren't rigged to not idle more than 5 minutes without having to run up and push the clutch all the time, then i'd idle.

 

ahh yes. shore power. that would make it pretty easy. i wasn't sure if they had something like that or not. hopefully whatever system i end up with does.