CELL COUNT DETERMINATION DEVICE, CHARGER, BATTERY PACK, AND CHARGING SYSTEM

A cell count determination device is configured to determine a cell count of a battery pack having installed therein a plurality of battery cells. The cell count determination device includes a plurality of switch elements provided in association with the plurality of battery cells, which can be increased or decreased in number in the battery pack. Each of the switch elements is configured to enter a conductive state if, while connected to the battery pack, a corresponding battery cell is present, and enter a non-conductive state if the corresponding battery cell is not present. The cell count determination device further includes a determination unit that is configured to determine the cell count of the connected battery pack on the basis of a combination of conductive states and non-conductive states among the plurality of switch elements.