To re-charge the solar charger,simply open the cover and face in the daylight.If possible,face in the direction of sun on a sunny day. It takes about 3-5 hours to fully recharge the charger depending on the intensity of the light. The solar charger can also be re-charged with electricity using the power adapter supplied(AC). The solar charger has a built in Li-battery which can support your mobile phone hours of talk time depending on the size of built-in batteries and models of your mobile phone.