[sanddrag]

I don't think you're going to get that kind of capacity outof NiMH or NiCd unless you go in parallel with a bridge rectifier setup. I don't know that much about putting NiCds or NiMHs in parallel. About the NiMH batteries themselves, the most common form is Sub-C size cells with 1.2V each and up to 3800mAh of capacity each. You can buy them preassembled in series in packs for higher voltage. But then you'd want multiple packs in parallel for more capacity. However, I remember hearing that if a bridge rectifier is not used, the current will flow back and forth between the two until they discharge themselves.