variablecountbatterycharger

Variable Count Battery Charger

Charger Circuit For An Odd Number Of Batteries

Have you ever needed to charge an odd number of batteries when your battery charger required either 2 or 4 cells in order to complete the circuit? If so, here is a circuit that will allow you to charge a variable number of cells.

The transistor based current regulator sets the charge current. This can be fixed or variable.

Those three diodes across each cell connector limit voltage drop across that connection point to about 2.1 volts. If no battery is inserted in that position it will still conduct to charge those batteries that are inserted in other positions. These three diodes can be almost any silicon power diode, as long as they are rated higher than your charge current.

For battery voltages other than 1.5 volt cells, you may be able to use zener diodes in place of the power rectifier units.