During charging, a quick charging device forms a battery module series circuit by connecting a third contact of a first switch to a second contact of the first switch, and connecting a fifth contact of a second switch to a twelfth contact of the second switch, so as to enable a charger to be connected to the battery module series circuit. During discharging, the quick charging device forms a battery module parallel circuit by connecting the third contact of the first switch to a first contact of the first switch, and connecting the fifth contact of the second switch to a fourth contact of the second switch, so as to enable a load unit to be connected to the battery module parallel circuit.