| 摘要 |
PROBLEM TO BE SOLVED: To combine shortening of the required charging time and the deterioration suppression of a battery pack.SOLUTION: A battery pack has a series circuit of a plurality of cells. Relation of internal resistance and SOC (State Of Charge) is measured for each cell, and a SOC for which the internal resistance takes a maximum value is extracted as a peak SOC (SOC[1], SOC[2]). A range of SOC including a peak SOC is set as a range of peak SOC range for each cell, and when charging a battery pack, a current rate in the peak SOC range is set lower than a current rate in the SOC range (first SOC range) on the low SOC side of the peak SOC range, and a current rate in the SOC range (third SOC range) on the high SOC side of the peak SOC range for each cell. Reduction of current rate for each cell is achieved by bypassing a current to a bypass circuit connected in series with the cell. |
