Hyperion Samsung 2x1500mAh Battery + Charger for Samsung Google Nexus S/Nexus 4G (Also Compatible with Samsung D720, I9020, Code i220, Behold II T939, Samsung Instinct HD SPH-M850, Propel Pro i627) 2 x 1500mAh Battery and 1 x Universal Wall Dock Charger. Do not need to change back cover. The Smart LED shows charging status. Quick charge with automatic constant current control prevents battery from overcharging, short circuit, and electronic shock. Extend your talk time on your HTC Nexus S, Nexus S 4G, and many others. Easily swap your battery when your charge is low.