DJI phantom2 battery 

The Phantom 2 Quadcopter Battery is a 5200 mAh, 11.1 V lithium-polymer battery for Phantom 2 Quadcopters inlcuding the Phantom 2 with GoPro mount and Phantom 2 Vision. It slots into an opening the tail of the Phantom 2 Vision Quadcopter and features four LEDs that display remaining capacity. Power management is handled internally meaning the battery doesn't require a separate balance lead to control charging.

Because it features its own power regulation, the Phantom 2 Quadcopter Battery is only suitable for use with the Phantom 2 Charger.