With my 3 kids sweatily sweltering in the rear of this tin can I decided the maxxair vent would have to trump (the only time you'll catch me using the word) other projects on the list, namely the house battery system. So where to wire it? Direct to the main battery or should I splice into a 12v line? After installing the vent today I tried to cut it into the rear 12v charger to no avail. From what I've read I'm thinking the brains said "no". I was able to draw some power in the form of constant beeping from the vent unit. Any thoughts? I've future plans to isolate all of the non-critical draws to a house system but in the meantime I'd like to provide my kids at least a little relief. From the heat, they're gonna have to deal with me for a long time.