VEHICLE-BATTERY MANAGEMENT DEVICE AND OFFSET DETECTING METHOD OF CURRENT SENSOR

PROBLEM TO BE SOLVED: To provide a vehicle-battery management device that manages charging/discharging currents of a secondary battery with higher accuracy, and an offset detecting method of a current sensor that more accurately detects an offset in a current sensor used in the management device.SOLUTION: The vehicle-battery management device manages charging/discharging of a second battery BT by which power transfer to/from a traveling motor/generator takes place. The vehicle-battery management device is provided with: a current sensor AM for measuring a current of the secondary battery BT; a parallel circuit composed of a series circuit comprising the secondary battery BT and the current sensor AM, and a series circuit connected in parallel to the series circuit and comprising a first relay 13 and a resistor R1; a main relay 11 provided between the parallel circuit and the power transfer destination; and a battery management ECU 10 that controls opening/closing of the main relay 11 and the first relay 13 respectively separately from each other and calculates a current value applied to the charging/discharging of the secondary battery BT on the basis of the detection value detected by the current sensor AM.