... on the built-in battery, charging more safe, more full power, discharge the output as the standard USB socket interface 4 ... power percentage, to push the " OFF " symbol is closed, to push the bulb for lighting state,Fits for iPhone,cellphone,MP3,MP4,GPS,IPAD ... effects over 1,000 cycles3) Built-in rechargeable U7800Ahigh capacity portable power bank/Backup External Battery Pack Charger for mobile device