iPhone4 external battery

Item/Spe: NP-IP4A Normal capacity: 2300MAH Real capacity:2300MAH Output voltage: 5V Output current: 500mA Input voltage: 5V Input current: 500mA Charging time: 3 4 hours Accesssories:Accessories: USB line,Iphone 4G protector iPhone4 external battery specification: 1. Battery + protector,solved the signal problem perfectly 2. With data transfer function, connected with PC and iTunes synchronous. 3. Equipped with intelligent switch, extended the built-in battery service life,more safe. 4. Accurately display electronic capacity, the LED light will be flicker when low capacity. 5. Full covered packing design, perfect fit for iPhone4. 6. Standby time: ≥400 hours 7. Holding time: over 7 hours by 3G net / over 13.5 hours by 2G net 8. Online time: over 7 hours by 3G net / over 8 hours of Wi-Fi using. 9. Music play: over 30 hours 10. Video play: over 8 hours Description: 1.designing beautiful, it is very thin, say goodbye to your bulky battery for iPhone. 2.double your battery life ---- 2300MAH stored insided. 3.protection to your iPhone from knocks and scratches with its hard shell case.