Battery pack and battery pack checking method

• US 6,873,135 B2
• Filed: 04/25/2002
• Issued: 03/29/2005
• Est. Priority Date: 04/25/2001
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nakatsuji, Toshiyuki
• Primary Examiner(s): Vu, Bao Q
• Application Number:
  US10/132,232
• Publication Number:
  US 20020195996A1
• Time in Patent Office: 1,069 Days
• Field of Search: 320/132, 320/134, 320/136
• US Class Current: 320/132
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 50/569 Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals battery terminal connectors with integrated measuring arrangements G01R31/364
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention is a battery pack with BMU mounted in the control circuit for controlling battery voltage, etc. In order to avoid worsening of the battery pack durability due to failure of suspension of charging when full-charge detection or over-charge detection is not executed at all because of trouble in the battery voltage measuring section, the battery pack comprises a self-checking section which integrates the charging capacity during charging and detects whether or not the charging capacity is higher than a set-value and turns OFF the charging FET, thereby executing the trouble checking of charging capacity.

Claims

1. A battery pack comprising:

a rechargeable battery;

a management/control unit for managing/controlling the charge and discharge of said rechargeable battery,

wherein said management/control unit comprises;

a current detecting resistor;

a charging current measuring section for measuring the charging current of said rechargeable battery that flows in the current detecting resistor;

a voltage detector for measuring the voltage of said rechargeable battery;

a temperature detector for measuring and detecting temperatures by means of a temperature sensor fitted to said rechargeable battery;

a charge control unit for receiving the outputs from said charging current measuring section, said voltage detector, and said temperature detector; and

a charge-and-discharge switch responsive to the charge control unit, and

said charge control unit including

a self-checking section for monitoring the charging and discharging operation of said rechargeable battery responsive to the output signals from at least one of said charging current measuring section and said voltage detector, and

a charging capacity integrating section, and in self-checking performed by the self-checking section of said charge control unit, only charging capacity during charging is integrated, and trouble checking is executed at the rechargeable battery or management/control unit by checking whether or not the charming capacity integrated per charging is higher than a specified valued.

2. The battery pack of claim 1, wherein the maximum value of charging capacity integrated per charging is set higher than the nominal capacity of rechargeable battery.

5. The battery pack of claim 1, wherein there is provided a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment.

6. The battery pack of claim 1, wherein the self-checking section comprises an information storing section that stores trouble information.

7. Electronic equipment, comprising:

the battery pack of claim 1 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section;

an input interface for inputting a signal showing the information obtained through trouble checking with respect to the battery pack; and

an indicator unit for indicating information obtained through the trouble checking.

8. Electronic equipment, comprising:

the battery pack of claim 1 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section,

wherein there is provided a charger which stops charging in accordance with trouble checking result information transmitted from said battery pack.

9. A trouble checking method for battery pack, that is a method of management/control of charging and discharging operation executed by a management/control unit disposed in the battery pack in charging and discharging of the battery pack of claim 1 according to the steps of:

checking for over-current, over-charge, and whether or not the temperature of rechargeable battery is within the range of setting;

turning OFF a charging FET (Field Effect Transistor) that is a semiconductor for switching a charge-and-discharge circuit;

detecting that charging current keeps flowing even with said charging FET forcibly turned OFF and executing trouble checking of said charging FET;

breaking a fuse disposed in the charge-and-discharge line;

integrating the charging capacity of the battery pack;

indicating the remaining amount of battery capacity; and

checking for charging capacity trouble,

wherein trouble checking of the battery pack is executed by a step of checking for charging capacity trouble, and

the step of checking for charging capacity trouble is performed between the step of integrating the charging capacity of battery pack and the step of indicating the remaining amount of battery capacity.

10. The trouble checking method for battery pack of claim 9, that is a method of checking for charging capacity trouble in charging and discharging of the battery pack, including the steps of:

clearing the integrated charging capacity when the operation mode is shifted;

controlling the charging capacity by a charging capacity integrating section in the charge control unit, controlling only the integration of charging capacity;

detecting charging capacity trouble by emitting a signal from the self-checking section when the value of charging capacity integrated during rechargeable battery charging exceeds a previously specified set-value;

forcibly turning OFF the charging FET;

informing the trouble to the equipment side through a communication unit; and

storing the trouble information in an information storing section.

11. The trouble checking method for battery pack of claim 10, wherein the maximum value of charging capacity integrated per charging is set to a value higher than the nominal capacity of rechargeable battery.

12. The trouble checking method for battery pack of claim 9, wherein remaining capacity trouble checking in charging and discharging of the battery pack includes the steps of:

detecting remaining capacity trouble by emitting a signal from the self-checking section when the remaining capacity during rechargeable battery charging exceeds a previously specified set-value;

forcibly turning OFF the charging FET;

informing the trouble to the equipment side through the communication unit; and

storing the trouble information in the information storing section.

13. The trouble checking method for battery pack of claim 12, wherein the maximum value of remaining capacity integrated by a remaining capacity managing section is set higher than the learning capacity of rechargeable battery.

14. The battery pack of claim 1, wherein there is provided a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment.

15. The battery pack of claim 2, wherein there is provided a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment.

18. The battery pack of claim 1, wherein the self-checking section comprises an information storing section that stores trouble information.

19. The battery pack of claim 2, wherein the self-checking section comprises an information storing section that stores trouble information.

22. Electronic equipment, comprising:

the battery pack of claim 1 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section;

an input interface for inputting a signal showing the information obtained through trouble checking with respect to the battery pack; and

an indicator unit for indicating information obtained through the trouble checking.

23. Electronic equipment, comprising:

the battery pack of claim 2 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section;

an input interface for inputting a signal showing the information obtained through trouble checking with respect to the battery pack; and

an indicator unit for indicating information obtained through the trouble checking.

26. Electronic equipment, comprising:

the battery pack of claim 1 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section,

wherein there is provided a charger which stops charging in accordance with trouble checking result information transmitted from said battery pack.

27. Electronic equipment, comprising:

the battery pack of claim 2 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section,

wherein there is provided a charger which stops charging in accordance with trouble checking result information transmitted from said battery pack.

30. The trouble checking method for battery pack, that is a method of checking for charging capacity trouble in charging and discharging of the battery pack of claim 1, including the steps of:

clearing the integrated charging capacity when the operation mode is shifted;

controlling the charging capacity by a charging capacity integrating section in the charge control unit, controlling only the integration of charging capacity;

detecting charging capacity trouble by emitting a signal from the self-checking section when the value of charging capacity integrated during secondary battery charging exceeds a previously specified set-value;

forcibly turning OFF the charging FET;

informing the trouble to the equipment side through a communication unit; and

storing the trouble information in an information storing section.

31. The trouble checking method for battery pack, wherein remaining capacity trouble checking in charging and discharging of the battery pack of claim 1 includes the steps of:

detecting remaining capacity trouble by emitting a signal from the self-checking section when the remaining capacity during secondary battery charging exceeds a previously specified set-value;

forcibly turning OFF the charging FET;

informing the trouble to the equipment side through the communication unit; and

storing the trouble information in the information storing section in BMU 1.

3. A battery pack comprising:

a rechargeable battery;

a management/control unit for managing/controlling the charge and discharge of said rechargeable battery,

wherein said management/control unit comprises;

a current detecting resistor;

a charging current measuring section for measuring the charging current of said rechargeable battery that flows in the current detecting resistor;

a voltage detector for measuring the voltage of said rechargeable battery;

a temperature detector for measuring and detecting temperatures by means of a temperature sensor fitted to said rechargeable battery;

a charge control unit for receiving the outputs from said charging current measuring section, said voltage detector, and said temperature detector; and

a charge-and-discharge switch responsive to the charge control unit, and

said charge control unit including

a self-checking section for monitoring the charging and discharging operation of said rechargeable battery responsive to the output signals from at least one of said charging current measuring section and said voltage detector and

wherein the charge control unit includes a remaining capacity managing section capable of integrating remaining capacity until establishment of a full-charge condition, said battery pack performing trouble checking by determining whether said integrated remaining capacity goes above a specified value during charging.

4. The battery pack of claim 3, wherein the maximum value of remaining capacity value integrated by the remaining capacity managing section is set higher than the learning capacity of rechargeable battery.

16. The battery pack of claim 3, wherein there is provided a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment.

17. The battery pack of claim 4, wherein there is provided a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment.

20. The battery pack of claim 3, wherein the self-checking section comprises an information storing section that stores trouble information.

21. The battery pack of claim 4, wherein the self-checking section comprises an information storing section that stores trouble information.

24. Electronic equipment, comprising:

the battery pack of claim 3 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section;

an input interface for inputting a signal showing the information obtained through trouble checking with respect to the battery pack; and

an indicator unit for indicating information obtained through the trouble checking.

25. Electronic equipment, comprising:

the battery pack of claim 4 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section;

an input interface for inputting a signal showing the information obtained through trouble checking with respect to the battery pack; and

an indicator unit for indicating information obtained through the trouble checking.

28. Electronic equipment, comprising:

the battery pack of claim 3 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section,

wherein there is provided a charger which stops charging in accordance with trouble checking result information transmitted from said battery pack.

29. Electronic equipment, comprising:

the battery pack of claim 4 comprising a communication unit which receives the output of the self-checking section and delivers the information to externally connected electronic equipment, and an information storing section for storing trouble information in said self-checking section,

wherein there is provided a charger which stops charging in accordance with trouble checking result information transmitted from said battery pack.

32. A battery pack comprising:

a rechargeable battery;

a management unit for managing and controlling the charge and discharge of the rechargeable battery, said management unit comprising;

a switch for controlling the charge and discharge of the rechargeable battery;

a self-checking section;

a current detector for detecting current flowing in the battery and providing a first output signal to the self-checking section relating to the current;

a voltage detector for measuring the voltage of the battery and providing a second signal to the self-checking section related to the voltage;

a charging capacity integration section for integrating charging capacity and for providing a third output signal responsive to an upper limit of integrated capacity;

wherein the self-checking section turns-off the switch, upon termination of current detection and voltage detection, in response to the third signal.