DESC: This most powerful portable rechargable 3G IPhone backup battery will extend 3G IPhone, ITouch battery life to 500%. Its capacityis 5000 mAh at 3.7V output voltage. It can powerup your mobile devicesthrough USB cable adapter. Battery pack is compact, light in weight (130g) and eco-friendly. Boost 3G IPhone internet time to 38 hours, audio time to 180 hours. It can power all the latest IPhones, IPod, ITouch, Nano, IPod Video, Classic. It can also power G1, Blackberry, PDA, Nintendo Gamboy etc. Allow you to watch 11 movies on air plane with this 3G iPhone itouch external backup battery and you will not need to worry about 3G iPhone battery life any more!