Abstract: A desulfation device 10 drives its switching circuit 140 by using a pulse wave drive signal having a pulse width of 1.6 ?sec and a frequency of 20000 Hz. The switching circuit 140 is switched on to allow extraction of electric current of 500 mA from a battery via a resistor R1, while being switched off to stop the extraction of electric current. When the switching circuit 140 is switched off, a back electromotive force and a reverse current of 500 mA are supplied to the battery. The supplied reverse current is negative current in the form of spikes. This electric current acts on electrodes of the battery and thereby enables removal of sulfation on the electrodes of the battery, while reducing a temperature increase of the desulfation device 10 during its operation.