Feature: Under the sunlight, the built in solar panel can transform sunlight into DC electricity, then give powerful charge to the batteries. The amount of electricity produced varies according to the strength of sunlight. When under full sun (1000W/?), the solar cell produces Min. 600mA per hour. For 9V battery charging, the solar cell produces Min. 20mA per hour. Note: (1).When the solar battery charger is not in use, please slide the ON/OFF switch to OFF position, else product will drain power in the battery. (2).Please make sure the battery(s) are placed in proper polarity. “+” indicates positive, and “-” indicate negative. (3).This product is not fully waterproof, it is only splash proof. Please do not left it outside during rainfall or submerge in water. (4).Keep the solar cell clean with a soft cloth for producing more power.(5).Compare to the AC battery charger, the solar charger would be a little bit slow. (6).It is better to charge at least 2pcs 1.2v battery together.