Most cell phone users have the unpleasant experience. The cheap phone battery was fully charged last night while it is low in the next noon. If there is high quality charger which can protect your battery, that will be great! Anytone 1800mAh rechargeable external battery backup charger for iPhone 3G 3GS. Superior iPhone 3G 3GS battery is designed for people who has busy calls, who need longer talking time, and who go without an access to an external charging alternative. Enjoy extended use of your mobile phone using this backup phone battery. Superior iPhone 3G 3GS battery extends the time that you can use your device -ideal for long flights, outdoor activities, and business trips.Easy to use and charge with your usb cable and the power will be stored in the power station. Then simply plug the power station to your iPhone for charging at any where you go. Featuring high technology, this cheap phone batteries conserve power while efficiently and conveniently running your phones.