BATTERY HEATING DEVICE

A battery heating device includes: a capacitor connected in parallel between a battery and a load; a reactor connected to the capacitor; a first switch connected to a terminal on the load side of the reactor, and to one terminal of the capacitor; a second switch connected to a terminal on the load side of the reactor, and to another terminal of the capacitor; a controller configured to control an ON/OFF state of the first switch and the second switch; and a current sensor configured to detect a direction and a current value of a reactor current flowing in the reactor. The controller performs battery heating mode control including a first control of turning OFF the first switch and turning ON the second switch when a current value becomes substantially zero from a state where the reactor current flows from the load side to the battery side.