Charge state equalization apparatus and assembled battery system including the same

摘要

A state-of-charge equalizing device equalizes the state of charge of each of cells connected in series to form an assembled battery, and comprises charging/discharging circuits connected in parallel to the respective cells to discharge and/or charge the respective cells, voltage measurement circuits connected to the respective charging/discharging circuits to measure the voltages across the respective cells, and a control circuit. The control circuit comprises a unit calculating an equalization target voltage based on the measured voltages before the charge or discharge starts, a unit starting discharging/charging the cells having a voltage thereacross different from the target voltage, a unit correcting the target voltage to thereby calculate a corrected equalization target voltage for each of those cells based on the difference between the measured voltages before and at a certain time period after the charging/discharging, and a unit ending the discharging/charging when the measured voltage reaches the corrected target voltage.