IN-VEHICLE BACKUP POWER SUPPLY CONTROL DEVICE AND IN-VEHICLE BACKUP POWER SUPPLY

Provided is an in-vehicle backup power supply control device or an in-vehicle backup power supply configured to generate a notification indicating the state of a power storage unit to an external device. When a main power supply fails, a control device applies a voltage to a backup target load from a power storage unit. The control device is provided with a charging/discharging unit for charging the power storage unit and discharging the power storage unit, a voltage detection unit for detecting a voltage of the power storage unit, a control unit for controlling the operation of the charging/discharging unit, and a signal interruption unit for interrupting the output of the predetermined signal to a device external to the control device in a case where the voltage value (Vout) of the power storage unit detected by the voltage detection unit is smaller than a predetermined first threshold.