... over-voltage protection. Advantages solar led light With mini USB output to charge mobile phones, iphone, PDA ... special knowledge to maintain and operate the devices.4 mobiles tips for different phone modelsLong lighting time ... and damageIn order to keep the battery a long cycle life, please charge the battery at least ... 20w indoor solar led light(2/4/6 LED lights,5V/12V output,mini solar fan optional)