4000mAh LiPo Transmitter Battery for DX7s, DX8The 4000 2S LiPo offers not only double the flight time as the stock DX8 battery but also advanced safety and control features. Longer flight and safer flight make for hours of fun for the whole family and your friends. Features: Built in cell balancer Built in safety current prevents overcharging Features: . It also includes a built in safety current that shuts the battery off, to avoid overcharging and damaging the battery and radio. Plus, a built