It uses 3-aaa cells.. I use nimh duracell and have never run till exhaustion so not sure.. I would say at least 3-4 hours before I see some dimished output then I re-charge. I have bought about 6 of these lights and put them in cars for emergency lighting, they work great.. Like I said at 70 lumens more of a be seen light. This is slightly brighter than my PT Eos light but about 1/5 the price. Seller I linked takes about 7-9 days to California from HK..