Battery charge/discharge current detection apparatus

• US 20090132188A1
• Filed: 10/06/2008
• Published: 05/21/2009
• Est. Priority Date: 11/19/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Watanabe, Hidemitsu
• Granted Patent: US 8,041,523 B2
• Time in Patent Office: Days
• US Class Current: 702/64
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The battery charge/discharge current detection apparatus has a power supply circuit powered by a battery mounted on a vehicle and configured to detect a charge/discharge current of the battery by use of a current detecting resistor connected between a negative terminal of the battery and a ground. The battery charge/discharge current detection apparatus includes a first function of detecting a voltage across the voltage detecting resistor, a second function of detecting a charge/discharge current of the battery on the basis of the voltage detected by the first function, a third function of detecting presence of an abnormality of the current detecting resistor, and a fourth function of informing an abnormality detected by the third function to the outside. The battery-side negative terminal of the power supply circuit is connected to the negative terminal of the battery.

Claims

1. A battery charge/discharge current detection apparatus having a power supply circuit powered by a battery mounted on a vehicle and configured to detect a charge/discharge current of the battery by use of a current detecting resistor connected between a negative terminal of the battery and a ground, the battery charge/discharge current detection apparatus comprising:

a first function of detecting a voltage across the voltage detecting resistor;

a second function of detecting a charge/discharge current of the battery on the basis of the voltage detected by the first function;

a third function of detecting presence of an abnormality of the current detecting resistor; and

a fourth function of informing an abnormality detected by the third function to the outside;

wherein a battery-side negative terminal of the power supply circuit is connected to the negative terminal of the battery.

2. The battery charge/discharge current detection apparatus according to claim 1, wherein the third function detects presence of an abnormality of the current detecting resistor on the basis of the voltage across the current detecting resistor detected by the first function.

3. The battery charge/discharge current detection apparatus according to claim 1, further comprising a fifth function of detecting a temperature of the current detecting resistor, the third function detecting presence of an abnormality of the current detecting resistor on the basis of the temperature detected by the fifth function.

4. The battery charge/discharge current detection apparatus according to claim 3, wherein the fifth function includes a heat-sensitive element thermally connected to the current detecting resistor.

5. The battery charge/discharge current detection apparatus according to claim 1, wherein the fourth function informs an external control device of occurrence of an abnormality through radio communication with the external control device.

6. The battery charge/discharge current detection apparatus according to claim 1, wherein the fourth function includes means for visually or audibly indicating an abnormality detected by the third function.

7. The battery charge/discharge current detection apparatus according to claim 1, further comprising a fifth function of forming a bypass of the current detecting resistor when the third function detects an abnormality of the current detecting resistor.

8. The battery charge/discharge current detection apparatus according to claim 7, further comprising a sixth function of producing a state where the voltage across the current detecting resistor is virtually zero, and performing a zero-point correction for the second function in the produced state.

9. The battery charge/discharge current detection apparatus according to claim 1, wherein the first function includes two diodes parallel-connected to the current detecting resistor in opposite polarity directions to each other.