Regarding the Battery Thingy:
This subject has been discussed at least Quarterly on here and we found out some time ago that just using power off your vehicle's battery is jus fiin. (mo Ebonics) To that end, I went to a Radio Shack this winter and found a cord that will plug into my "Hot" power receptical on my Grand Caravan and run all the way back to a plywood shelf I lay across the area where the rear seat would be on the arm rest areas. This is in case I am hard pressed for power but I have found 110v at most every place I have shot at in several years.