Battery controller

1. A battery controller that controls a battery for supplying driving power to a load apparatus, comprising:

a current detection unit that detects a discharge current to be discharged from the battery and a charge current to be charged to the battery;

a malfunction detection unit that detects malfunction of a voltage detector for detecting a voltage of the battery; and

a contactor control unit that controls opening/closing of a contactor provided on a power supply line through which the discharge current and the charge current flow, the power supply line connecting the battery and the load apparatus,

wherein the contactor control unit integrates the charge current and the discharge current detected by the current detection unit when the malfunction of the voltage detector is detected by the malfunction detection unit, calculates an actual charge current amount which is obtained by subtracting an integrated value of the discharge current from an integrated value of the charge current, and prohibits charging/discharging to and from the battery by controlling the contactor to be opened when the actual charge current amount is equal to or more than a predetermined value.

2. The battery controller according to claim 1 , wherein

the load apparatus is a traveling motor of an electric power vehicle, the discharge current is used to run the traveling motor, and the charge current is generated by regeneration of the traveling motor.

3. The battery controller according to claim 2 , wherein

a body of the electric vehicle is provided with a charge and discharge connector that is connectable to an external charger for charging the battery or an external device for driving using power of the battery, and

the discharge current is used to drive the external device, and the charge current is supplied from the external charger.

4. The battery controller according to claim 1 , further comprising:

a state-of-charge calculating unit that calculate a state of charge of the battery based on the voltage detected by the voltage detector,

wherein the contactor control unit sets a predetermined value based on the state of charge calculated using the voltage immediately before the malfunction of the voltage detector is detected.

5. The battery controller according to claim 2 , further comprising:

a state-of-charge calculating unit that calculate a state of charge of the battery based on the voltage detected by the voltage detector,

wherein the contactor control unit sets a predetermined value based on the state of charge calculated using the voltage immediately before the malfunction of the voltage detector is detected.

6. The battery controller according to claim 3 , further comprising:

a state-of-charge calculating unit that calculate a state of charge of the battery based on the voltage detected by the voltage detector,

wherein the contactor control unit sets a predetermined value based on the state of charge calculated using the voltage immediately before the malfunction of the voltage detector is detected.

7. The battery controller according to claim 4 , wherein the higher the state of charge calculated based on the voltage detected by the voltage detector immediately before the malfunction of the voltage detector is detected is, the smaller the predetermined value to be set by the contactor control unit is.

8. The battery controller according to claim 5 , wherein the higher the state of charge calculated based on the voltage detected by the voltage detector immediately before the malfunction of the voltage detector is detected is, the smaller the predetermined value to be set by the contactor control unit is.

9. The battery controller according to claim 6 , wherein the higher the state of charge calculated based on the voltage detected by the voltage detector immediately before the malfunction of the voltage detector is detected is, the smaller the predetermined value to be set by the contactor control unit is.

10. The battery controller according to claim 1 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

11. The battery controller according to claim 2 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

12. The battery controller according to claim 3 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

13. The battery controller according to claim 4 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

14. The battery controller according to claim 5 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

15. The battery controller according to claim 6 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

16. The battery controller according to claim 7 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

17. The battery controller according to claim 8 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

18. The battery controller according to claim 9 , wherein the higher a temperature of the battery is, the smaller the predetermined value to be set by the contactor control unit is.

19. The battery controller according claim 1 , further comprising:

a notification unit that notifies the malfunction to a user when the malfunction of the voltage detector is detected by the malfunction detection unit.