ORIGINAL: rclement
One of the guys at the field had one of those type and it worked for a while but he doesn't use it anymore, I think it wouldn't hold a charge anymore. Here's a picture of one that I put together out of cheap NiCad packs. It works great. You have to wire it so that you get more amps and not more volts.
How do you wire it so you get more amps and not more volts?