IN-VEHICLE BATTERY MANAGEMENT DEVICE

An in-vehicle battery management device includes a controller configured or programmed to control a charge/discharge device such that the charge/discharge device performs charge or discharge on an in-vehicle battery of an electric vehicle in a predetermined processing condition, the in-vehicle battery being connected to the charge/discharge device. The controller includes a calculator configured or programmed to calculate a degree of deterioration progress of the in-vehicle battery based on charge/discharge information in the charge or discharge; and a communicator configured or programmed to notify a predetermined notification target of the calculated degree of deterioration progress.