A charging/discharging system that is adapted to be interposed between a system power supply and a storage battery and performs charging/discharging of the storage battery, the charging/discharging device system comprising: a charging/discharging-device that is adapted to electrically connect to the system power supply; a charging/discharging connector that is adapted to electrically connect the storage battery and the charging/discharging device and includes a lock mechanism that is adapted to maintain a mechanical connection state of the charging/discharging connector; a solenoid that operates the lock mechanism; and a switch that interlocks with the lock mechanism; and a charging/discharging cable that is connected to the charging/discharging connector at one end; the charging/discharging-device comprising: a power conversion unit that operates as an AC/DC converter when AC power is input, and operates as a DC/AC converter when DC power from the storage battery is input; a control unit that controls an operation of the power conversion unit; and in response to a signal (11 d) that is output from the control unit, an abnormality detection unit that feeds power to the solenoid and outputs an abnormality detection signal on a basis of the signal (11 d) that is output from the control unit and a signal output from the switch that interlocks with the lock mechanism. a charging/discharging-device that is adapted to electrically connect to the system power supply; a charging/discharging connector that is adapted to electrically connect the storage battery and the charging/discharging device and includes a lock mechanism that is adapted to maintain a mechanical connection state of the charging/discharging connector; a solenoid that operates the lock mechanism; and a switch that interlocks with the lock mechanism; and a lock mechanism that is adapted to maintain a mechanical connection state of the charging/discharging connector; a solenoid that operates the lock mechanism; and a switch that interlocks with the lock mechanism; and a charging/discharging cable that is connected to the charging/discharging connector at one end; the charging/discharging-device comprising: a power conversion unit that operates as an AC/DC converter when AC power is input, and operates as a DC/AC converter when DC power from the storage battery is input; a control unit that controls an operation of the power conversion unit; and in response to a signal (11 d) that is output from the control unit, an abnormality detection unit that feeds power to the solenoid and outputs an abnormality detection signal on a basis of the signal (11 d) that is output from the control unit and a signal output from the switch that interlocks with the lock mechanism. a power conversion unit that operates as an AC/DC converter when AC power is input, and operates as a DC/AC converter when DC power from the storage battery is input; a control unit that controls an operation of the power conversion unit; and in response to a signal (11 d) that is output from the control unit, an abnormality detection unit that feeds power to the solenoid and outputs an abnormality detection signal on a basis of the signal (11 d) that is output from the control unit and a signal output from the switch that interlocks with the lock mechanism.