Readytosky Lipo Battery Checker RC Battery Low Voltage Buzzer Alarm Voltage Tester Monitor for 1-8S Lipo Life LiMn Li-ion Battery(4PCS)
 
Product Features
  

         
Wide use range - Use for 1-8s lipo/li-ion/limn/li-fe rc drone battery.
         
Small Size - 1.57*0.91*0.43 Inch, Weight: 10g/1pc.
         
Super loud - Super loud alarm sound makes it easier to find your drone.
         
Easy to use -Just plug into the balance plug, the LED will cycle through the individual cell voltages as well as list the total voltage.
         
Display Mode: Battery cell voltages, total voltages, lowest cell voltage, Remaining battery capacity.