Apple iPhone 3G External Backup Battery,Charging cradle iPhone Case with Build-in Rechargeable battery Charge with your own iPhone adapter cable and the power will be stored in the power station Light indicator Red Indicator: battery is charging OFF: for using iPhone battery only without charging ON: for using the secondary battery and charge the iPhone Act as an extra battery or charging cradle for iPhone 3G EXTENDED Capacity   2250mAh                    Type    LI-PL Voltage      3.7V                              Condition    BRAND NEW                                                 Warranty    12 months