My revamped , faster, better , bionic (not) 4xAA rechagable battery charger.
Added an extra cell so it charges that much faster . Will charge 4 aa's in around 6 hours (thats 4 2000mAh NiMh) in full sun. Cost me about 50cents for the battery clip and the rest were scrap parts. (there is also a web site that sells scap solar cell dirt cheap. about $16 per pound in weight).