BATTERY PACK FOR PRACTICAL LOW-POWER MODE CURRENT DETECTION AND METHOD OF DETECTING EXCESSIVE CURRENT

• US 20120032645A1
• Filed: 08/03/2011
• Published: 02/09/2012
• Est. Priority Date: 08/04/2010
• Status: Abandoned Application

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Toyoda, Kazuhiro, MATSUURA, Shinichi
• Application Number:
  US13/197,102
• Publication Number:
  US 20120032645A1
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

In a battery pack 10 control section 5 low-power mode, a comparator 81 is used to detect the voltage across a 2.5 mΩ current detection resistor 2 connected in the battery 1 charging and discharging path. When the detected voltage exceeds a voltage (2.4 mV) that is lower than the voltage (50 mV) for detecting a 20 A first over-current in the non-low-power mode, that occurrence is recorded in a register 82. When the register 82 holds occurrence of the voltage being exceeded and when a CTRL signal indicating the load device 20 is in the low-power mode is input to an I/O port 55, the control section 5 CPU 51 detects a second over-current of approximately 1 A, switches OFF the cut-off devices 7, and sends advisory data from a communication section 9 to a control and power source section 21 in the load device 20.

Claims

1. A battery pack comprising:

rechargeable batteries;

a resistor connected in the rechargeable battery charging and discharging circuit path where operation is possible in a reduced power consumption low-power mode and in a non-low-power mode, and when detected resistor voltage exceeds a first voltage in the non-low-power mode, first operations are performed;

an input section where a prescribed signal is input;

an input decision section that determines whether or not a signal has been input to the input section; and

a voltage decision section that determines whether or not the voltage detected across the resistor in the low-power mode exceeds a second voltage that is lower than the first voltage,

wherein when the voltage decision section determines that detected voltage exceeds the second voltage and the input decision section determines that a signal has been input, the battery pack is configured to perform the first operations or second operations, which are different than the first operations.

2. The battery pack as cited in claim 1 wherein a memory section is provided that records occurrence of detected voltage exceeding the second voltage;

when detected voltage exceeds the second voltage, the voltage decision section stores that occurrence in the memory section; and

further, when that occurrence has been stored in the memory section, the battery pack is configured to judge the detected voltage greater than the second voltage.

3. The battery pack as cited in claim 1 wherein the prescribed signal is a signal indicating that an external electrical device for charging and discharging the rechargeable batteries is in the second low-power mode.

4. The battery pack as cited in claim 1 wherein switching devices are provided in the rechargeable battery charging and discharging path, and the second operations include switching the switching devices OFF.

5. The battery pack as cited in claim 1 wherein a communication section is provided to communicate with an external electrical device, and the second operations include writing advisory data into the communication section to notify the electrical device.

6. The battery pack as cited in claim 1 wherein the first operations include detecting a first over-current flowing in the resistor based on the voltage across the resistor, and the second operations include detecting a second over-current, which is smaller than the first over-current, based on the voltage across the resistor.

7. A method of detecting excessive current that detects a second over-current that is smaller than a first over-current in a battery pack provided with rechargeable batteries and a resistor connected in the rechargeable battery charging and discharging path where operation is possible in a reduced power consumption low-power mode and in a non-low-power mode, and when detected resistor voltage exceeds a first voltage in the non-low-power mode, first operations are performed, the method comprising:

establishing an input section for inputting a prescribed signal;

determining whether or not a signal has been input to the input section;

determining whether or not detected resistor voltage in the low-power mode exceeds a second voltage that is lower than the first voltage; and

detecting the second over-current when it is judged that the second voltage has been exceeded and a signal has been input.

8. The method of detecting excessive current as cited in claim 7 wherein a memory section is established that records occurrence of the detected voltage exceeding the second voltage;

when detected voltage exceeds the second voltage, that occurrence is stored in the memory section; and

when that occurrence has been stored in the memory section, the detected voltage is judged to exceed the second voltage.