In response to PM from Paul, other than a group buy order of 1/2D NiMH 3,800mAh ($7-8 each) from Powerstream, these are the only other "easy" and relatively affordable NiMH solution. I'm not vouching for the quality, but the price is right:
http://www.batteryjunction.com/streamlight-fb-5h1.html
They don't have individual cells in stock. I'm not sure how old these are, and/or condition of individual cells, balance with each other, actual mAh at needed discharge rate, etc. etc. , but at $5/cell assembled, that's worth a try.
http://www.batteryjunction.com/streamlight-fb-5h1.html
They don't have individual cells in stock. I'm not sure how old these are, and/or condition of individual cells, balance with each other, actual mAh at needed discharge rate, etc. etc. , but at $5/cell assembled, that's worth a try.