According to one embodiment, a charging method for an assembled cell including a plurality of secondary batteries connected in series is disclosed. The method can detect the cell voltages. The method can set a charging current setting value so as to lower the charging current setting value of the assembled cell, if at least one of the detected cell voltages reaches a predetermined charge termination upper limit voltage. The method can control the charging current of the assembled cell according to the charging current setting value. In addition, the method can stop the charge, when a lowest cell voltage is lower than a predetermined charge termination lower limit voltage at a time when at least one of the cell voltages detected reaches the charge termination upper limit voltage.