US Patent 11277012 Battery control unit and battery system

A plurality of switching units is provided for each of a plurality of batteries. The switching units switch between a connected state where the corresponding battery is connected in series with another battery and a non-connected state where series connection between the corresponding battery and the other battery is disconnected. A control unit controls the switching unit corresponding to the battery to switch to the non-connected state when it is determined that the corresponding battery reaches a charge end voltage during charging or a discharge end voltage during discharging. The control unit changes the charge end voltage such that the charge end voltage of the battery deteriorated is lower than the charge end voltage of the battery not deteriorated, or changes the discharge end voltage such that the discharge end voltage of the battery deteriorated is higher than the discharge end voltage of the battery not deteriorated.