Hyperion HTC Thunderbolt 4G 2x1500mah Battery + Charger (Also compatible with HTC Merge, MyTouch 4G, and Lexikon) Extend your talk time on your HTC Thunderbolt 4G, Merge, MyTouch 4G, Lexikon, or Slider with 2 new high quality batteries! Easily swap your battery when your charge is low. The battery has an integrated microchip to prevent overcharging and lengthens battery life. 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.