LOL this is a great thread as its what I do
Lots of ways to create a dual battery system with various benefits. There are some pretty kool ACRs (auto charge relays) out there two.
We use lots of stuff from these guys but home brew gear can be just as effective
http://www.inpowerdirect.com/auxiliarybatteryswitches.php
Thanks for that link, toying with the idea of adding a 2nd battery to the jeep,but I need to move the airbox first, which means adding a snorkel(so far the only plausible way I can see to make room for that second battery under the hood-I don't want it inside the vehicle) The snorkel kit bypasses the factory airbox, which means it can be removed, and it's just the right amount of space for a 2nd battery. I don't have much use for a snorkel, yet. Maybe after I add front and rear lockers........ARB for the back, lunchbox locker for the front. Those ARB's are expensive!! Never did understand why a front locker wasn't standard on all Jeeps..... A front locker will get you out of a lot of tight jams, been a couple of times I wish I had one. The rear locker is overkill, but you never know when you'll need it. When this Jeep gets retired from street use, it will become a toy to play in the mud with. May not be long now, the motor has already started the jeep death rattle. I have a spare motor, trans, transfer case and axles.....This one just passed 260,000 hard miles.