CHARGING/DISCHARGING CONTROL DEVICE AND CHARGING/DISCHARGING CONTROL METHOD

Provided is a charging/discharging control device () which, for an assembled battery () including a plurality of storage batteries () connected in series, detects capacity variation among the storage batteries () and controls charging/discharging of the assembled battery (). The charging/discharging control device () of the present invention includes a charging/discharging control unit () which calculates an electric-charge-quantity corresponding value which is a value corresponding to an electric charge quantity of the assembled battery (), on the basis of a current value of the assembled battery (), and calculates, as a voltage second-order derivative value, a value obtained through second-order differentiation of open-circuit voltage of the assembled battery () with respect to the electric-charge-quantity corresponding value. When a predetermined charging-stop condition is satisfied, the charging/discharging control unit () performs control to stop charging, and determines whether or not there is capacity variation among the plurality of storage batteries () in the assembled battery (), on the basis of the voltage second-order derivative value when the charging-stop condition is satisfied.