One for all size rechargeable NiMH / NiCd batteries Powered by both an external AC adapter (110V AC input ) and Car lighter Plug, so you can charge battery either in home or in a Car. Intelligent microprocessor controlled to cut power automatically once battery get fully charged Battery life well protected by negative delta V - delta V detection, and timer protection of AAA, AA, C, D and 9V size batteries. Use constant current pulse charging system Recharges NiMH / NiCd batteries 2 pcs or 4 pcs at a time for AA / AAA /C/D and 1-2 pcs of 9V cells Automatic charge current selection for the different size of batteries.