Patent ID: 6984961

Claim:
A battery assembly system comprising: a battery assembly comprising a plurality of storage batteries connected in series, a voltage detector for detecting respective voltages generated in the storage batteries constituting the battery assembly, a current detector for detecting a current flowing in the plurality of storage batteries, a state-of-charge (SOC) calculator for calculating the state of charge (SOC) of the storage batteries, based on the voltages detected by the voltage detectors, respectively and the current detected by the current detector, a charging/discharging unit for charging or discharging one of the plurality of storage batteries so as to equalize the SOC of the storage batteries calculated by the SOC calculator, respectively, and a deviation judging unit for judging whether a maximum value of the deviation of the SOC of each storage battery calculated by the SOC calculator exceeds a predetermined value, wherein the charging/discharging unit is capable of being connected selectively to each of the plurality of storage batteries, and when the deviation judging unit judges that the maximum value of the deviation of the SOC of each storage battery exceeds the predetermined value, the charging/discharging unit charges or discharges at least one of the plurality of storage batteries.