For source batteries for your chargers you might consider 2ea 6v golf cart batteries. Motorhomes went to these a long time ago because they give better duration than equivilant 12v batteries. I purchased 2 golf cart batteries that each weigh about 77 lbs. so lifting them individually is not a problem. I also purchased a nice marine battery box that houses both batteries together. I just leave these in the back of my Van most of the time, but have transferred them to other vehicles at times.

I haven't got lipoly's yet, but have been charging 32x2600 NiMH packs on my Schulze charger off the above batteries. Haven't run out of power yet, but probably haven't recharged more than 4 or 5 times at the field on any given day. Planning to get some of the next generation TP packs when they're released.

Norm