Test lithium coin cells and alkaline button cells quickly and easily with the voltcraft button cell tester simply insert the cell into the tester which will identify whether the cell is lithium or alkaline and indicate this via an led the 5 led show the remaining capacity of the cell at 1 led the cell needs replacing at 2 3 leds the cell is weak at 4 5 leds the cell is suitable to use as the tester has its own internal battery it does not drain the cells it is testing