2500mah Extended Battery Case Backup Power Bank Battery Charger Case (iOS 7 or above Compatible) for Apple iPhone 5 5S (Black + Purple) Emergency backup extended battery charger case, portable and convenient. Intelligent charging system with Smart power indication. Rechargeable li-polymer battery pack, recycle use for protect the environment. Charging your phone at any time anywhere if your cell phone without electricity. Security and stability, protective circuit for overcharging, over using and short circuit.