BATTERY PACK CHARGE SYSTEM AND BATTERY PACK CHARGE METHOD

摘要

PROBLEM TO BE SOLVED: To achieve more appropriate charging while preventing power loss for use as a battery pack by connecting a plurality of secondary cells in series to each other.SOLUTION: The battery pack charge system comprises: a charger 3 that charges a battery pack 20 with a constant current; connection/disconnection switches 4 that are provided at respective lithium ion cells 2 and connect and disconnect the cells 2 to/from the charger 3; and a controller 5 that monitors voltages of the respective cells 2 and controls the charger 3 and the respective connection/disconnection switches 4 on the basis of the voltages of the respective cells 2. The controller 5 disconnects the cells 2 from the charger 3 with the respective connection/disconnection switches 4 when a charging voltage of the cell 2 reaches at least an upper-limit voltage V.