[Tom Goldman]

Like RJ said, the East Coast Ultra Mini is my first choice for all the Stockers I build.
You might want to check out Anti Gravity Batteries . Their L Ion batteries are very dependable .
One other thing I would check is the master disconnect if you have one . ... I've seen several in the last few years that developed high resistance after a few minuets of use resulting in a voltage drop. Many of the older and a lot of the newer switches are only rated at 25 - 30 amps continuous .