This Battery Checker/Low Voltage Alarm connects to the JST/XH balance plug of a lipo battery (2 to 8 cells) and displays the voltage of each cell, as well as the total voltage of the battery.  It also features a loud alarm that can be set to activate if any one of the cells is below a preset minimum voltage. 

Setting the minimum cell voltage is easy. Simply plug the tester into the balance plug of the LIpo battery, and the voltage readout will light up and begin displaying the cell voltage sequence.  During this time, press the small button at the top of the checker above the digital readout; for each press of the button, the minimum voltage limit will change by increments of 0.10v.  The minimum voltage limit can be set for any increment of 0.10v, between 2.70v and 3.80v.  The low voltage alarm can also be shut off by pushing the button until the display reads "OFF" (when the low voltage alarm is off, the unit will continue to function as a cell voltage tester, but no alarm will sound if any cell is beneath the set minimum).