Maxpro Battery Monitor was developed by Maxpro Inc. in Jun 2006, it can be monitor your battery status in use, usually the voltage of battery will drop when it is using, so the Maxpro Battery Monitor will monitor the voltage and report the result to you with light and buzzer. Even use this monitor you can find any problems in your heli or airplane, it can help you to find your heli or airplane whether is health or not.  Very light weight and easy to install; just plug into your balance plug of your battery.  Note: this device use same balance plug as Align/E-flite/E-Sky/MegaPower batteries.  If you use Hyperion or Thunder Power or Flight power or Outrage XP packs, use the conversion wire.

Best investment for your lipo batteries.

>> Maxpro Battery Monitor User Manual