CHARGE CONTROL SYSTEM AND CHARGE CONTROL METHOD OF BATTERY PACK

摘要

PROBLEM TO BE SOLVED: To perform charging more properly while suppressing a discharge amount of a secondary battery, when a plurality of secondary batteries are used as a battery pack.SOLUTION: The charge control system comprises: a voltmeter 4 for monitoring a charging voltage of each of cells 2; bypass circuits 3 each having a discharging resistance 31 for discharging the corresponding cell 2; and a controller 6 for controlling each of the bypass circuits 3 on the basis of the charging voltage of the corresponding cell 2. The bypass circuits 3 can switch between a state in which the cell 2 discharges a small discharge current by activating the whole of the discharging resistance 31 and a state in which the cell 2 discharges a large discharge current by activating a part of the discharging resistance 31. When the charging voltage of the cell 2 is higher than a first predetermined voltage, the controller 6 allows the cell 2 to discharge with a small discharge current. When the charging voltage of the cell 2 is in a predetermined state, the controller 6 controls the bypass circuits 3 so that the predetermined cell 2 can discharge with a large discharge current.