1W Solar charger with USB input charging for AA/AAA NI-MH and NI-CD batteries This product is only suitable for AA/AAA NI-MH and NI-CD batteries. It can only charge four batteries at most each time. Put the batteris in this product and make sure the anode( ) and the cathode(-) are on right postion. Put this product face the sunlight while the LED light is turned on. that mean it is working. Take away the batteries after being full charged, Don't touch the batteries immediately cause it is too hot.