Very handy tool to have, allow you to see how much your battery is out of balance and how low did you drain your battery base on the total voltage of the pack.   

- Display individual voltage cell up to 6s Lipo.
- Display total voltage per battery pack.

Will be direct fit with, Fusion-Pack / Align / Air Thunder / Kong / other alike.

Note*  Does not fit with Thunder Power balance tab, require an adapter to fit those packs.

Estimate: How much capacity you have left.

4.20v = 100%
4.03v = 76%
3.86v = 52%
3.83v = 42%
3.79v = 30%
3.70v = 11%
3.6?v = 0%

Note*  Negative terminal is on bottom when facing the LED.