The charger in this project is designed to charge two AA NiMH or NiCd cells of any capacity (as long as they are the same) at about 470mA. It will charge 700mAh NiCds in about 1.5 hours, 1500mAh NiMHs in about 3.5 hours, and 2500mAh NiMHs in about 5.5 hours. The charger incorporates an automatic charge cut-off circuit based on cell temperature, and the cells can be left in the charger indefinitely after cut-off...
Howto create a USB battery charger
Posted on Sunday, Apr 29 2007 @ 05:36 CEST by Thomas De Maesschalck
Interested in creating your own USB powered NiMH and NiCD AA battery charger? Check out this guide over at Stefan's Electronics website to learn how to build such a device: