To enable accurately judging a full charged state, by preventing adverse influence like ripple in the charge operation of a battery.

A control circuit 7 drives and controls a driving motor 1 by supplying electric power from a battery group 6 via an inverter circuit 2. Batteries, e.g. fifteen batteries constituting the battery group 6 are charged from a three-phase AC power supply 16 by the control circuit 7 via a charger 8 and a rectification smoothing circuit 15. An IGBT 12 as a switching element of the charger 8 is PWM-controlled at the time of charge, and a charge current is detected by a current detection circuit 13. A detected voltage of a voltage detection circuit 10 is detected specified times, by using the zero-cross timing of the AC power supply which is detected by a zero-cross timing detection circuit 19 and the timing of PWM control, and the charged state of the battery group 6 is judged. Thereby judgement is always enabled under the same condition.