Method and apparatus for diagnosing the condition of a rechargeable battery

• US 7,227,335 B2
• Filed: 07/08/2004
• Issued: 06/05/2007
• Est. Priority Date: 07/22/2003
• Status: Active Grant

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Sakakibara, Kazuyuki, Fukumoto, Masaaki
• Primary Examiner(s): Tso; Edward H.
• Application Number:
  US10/887,428
• Publication Number:
  US 20050017686A1
• Time in Patent Office: 1,062 Days
• Field of Search: 320/127, 320/132, 320/149, 320/150, 324/426, 324/427, 324/430, 324/433
• US Class Current: 320/132
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• 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: Y02E 60/10 Energy storage using batteries

Abstract

A diagnostic technique for determining whether the degradation of a rechargeable battery is normal or abnormal is provided.

A device for determining whether the degradation of a rechargeable battery is normal or abnormal comprises a device for measuring a degradation indicator of a rechargeable battery 18, a device for determining the usage quantity of the rechargeable battery, and a device for comparing the usage quantity with a reference usage quantity in the case where the measured degradation indicator exceeds a reference degradation value.

Claims

1. A battery diagnosing device for determining whether a rechargeable battery has degraded normally or abnormally, comprising:

a device for determining a usage quantity that indicates how much the rechargeable battery has been used,

a device for measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity, and

a device for comparing a reference usage quantity with the determined usage quantity when the measured degradation indicator has exceeded a reference degradation value, wherein the reference usage quantity indicates how much the rechargeable battery can be used normally until the degradation indicator exceeds the reference degradation value.

2. A battery diagnosing device as set forth in claim 1, wherein,

the degradation indicator is one of:

the internal resistance, and

the charging/discharging capacity, and

the usage quantity is one of;

cumulative discharging time,

cumulative charging time,

cumulative discharged quantity of power,

cumulative charged quantity of power, and

cumulative number of charging cycles.

3. A battery diagnosing device as set forth in claim 2, wherein,

the usage quantity is modified based upon a frequency of occurrence of over discharging and/or over-rapid charging.

4. A diagnostic information collecting system, comprising:

a plurality of diagnosing devices, each of the plurality of diagnosing devices comprising;

a device for determining a usage quantity that indicates how much the rechargeable battery has been used,

a device for measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity, and

a device for comparing a reference usage quantity with the determined usage quantity when the measured degradation indicator has exceeded a reference degradation value, wherein the reference usage quantity indicates how much the rechargeable battery can be used normally until the degradation indicator exceeds the reference degradation value;

an information accumulating device for accumulating and storing diagnostic information that the plurality of diagnosing devices obtains through diagnoses of rechargeable batteries, and

a communication means for connecting the plurality of diagnosing devices and the information accumulating device via a computer network,

wherein the communication means transmits the diagnostic information obtained by the diagnosing devices to the information accumulating device.

5. A diagnostic information collecting system as set forth in claim 4, further comprising a reference value calculating means that extracts the relationship between the usage quantity and the degradation indicator from the diagnostic information accumulated by and stored in the information accumulating device, and calculates at least one reference value concerning to the degradation indicator or the usage quantity,

wherein the communication means transmits the reference value calculated by the reference value calculating means to at least one of the diagnosing devices.

6. A battery diagnosing device for determining whether a rechargeable battery is degrading normally or abnormally, comprising:

a device for determining a usage quantity that indicates how much the rechargeable battery has been used,

a device for measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity, and

a device for storing a reference degradation map, the reference degradation map being a two-dimensional map whose axes are the degradation indicator and the usage quantity and being divided into at least a normally degrading region and an abnormally degrading region, and

a device for determining whether the pair of the measured degradation indicator and the determined usage quantity belongs in the normally degrading region or the abnormally degrading region of the reference degradation map.

7. A battery diagnosing device for estimating a future usage quantity of a rechargeable battery, comprising:

a device for determining a usage quantity that indicates how much the rechargeable battery has been used,

a device for measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity,

a device for storing at least one pair of a previously measured value of the degradation indicator and a previously determined value of the usage quantity, and

a device for estimating, based upon the at least one pair of the previously measured/determined values and the pair of presently measured/determined values of the degradation indicator and the usage quantity, the future usage quantity that indicates how much the rechargeable battery can be further used until the degradation indicator exceeds a predetermined level.

8. A battery diagnosing device for estimating a future usage quantity of a rechargeable battery, comprising:

a device for determining a usage quantity that indicates how much the rechargeable battery has been used,

a device for measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity,

a device for storing a standard relationship between the change in the degradation indicator and increase of the usage quantity, and

a device for estimating, based upon the pair of the measured degradation indicator and the determined usage quantity, and the standard relationship, the future usage quantity that indicates how much the rechargeable battery can be further used until the degradation indicator exceeds a predetermined level.

9. A battery diagnosing device for determining whether a rechargeable battery is in an active state or a non-active state, comprising:

a device for measuring a first degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery,

a device for measuring a second degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery,

a device for storing a reference activity map, the reference activity map being a two-dimensional map whose axes are the first degradation indicator and the second degradation indicator and being divided into at least an active region and a non-active region, and

a device for determining whether the pair of the measured first degradation indicator and the measured second degradation indicator belongs in the active region or the non-active region of the reference activity map.

10. A battery diagnosing device as set forth in claim 9, wherein

the first degradation indicator is internal resistance of the battery, and

the second degradation indicator is charging/discharging capacity of the battery.

11. An adaptor with a battery diagnosing device and to be interposed between a charging device and a rechargeable battery, the battery diagnosing device comprising a device for measuring a first degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, a device for measuring a second degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, a device for storing a reference activity map, the reference activity map being a two-dimensional map whose axes are the first degradation indicator and the second degradation indicator and being divided into at least an active region and a non-active region, and a device for determining whether the pair of the measured first degradation indicator and the measured second degradation indicator belongs in the active region or the non-active region of the reference activity map, comprising:

a circuit for conducting a charging current from the charging device to the battery,

a circuit for discharging current from the rechargeable battery,

a circuit for selecting either the conducting circuit or the discharging circuit to function, and

a means for switching the selecting circuit such that the discharging circuit functions when the battery diagnosing device determines that the pair of measured degradation indicators is in the non-active region.

12. A battery diagnosing method for determining whether a rechargeable battery has degraded normally or abnormally, comprising:

determining a usage quantity that indicates how much the rechargeable battery has been used,

measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity,

comparing a reference usage quantity with the determined usage quantity when the measured degradation indicator has exceeded a reference degradation value, wherein the reference usage quantity indicates how much the rechargeable battery can be used normally until the degradation indicator exceeds the reference degradation value.

13. A battery diagnosing method for determining whether a rechargeable battery is degrading normally or abnormally, comprising:

determining a usage quantity that indicates how much the rechargeable battery has been used,

measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity, and

determining whether the pair of the measured degradation indicator and the determined usage quantity belongs in a normally degrading region or a abnormally degrading region of a reference degradation map, the reference degradation map being a two-dimensional map whose axes are the degradation indicator and the usage quantity and being divided into at least the normally degrading region and the abnormally degrading region.

14. A battery diagnosing method for estimating a future usage quantity of a rechargeable battery, comprising:

determining a usage quantity at least twice, the usage quantity indicating how much the rechargeable battery has been used,

measuring a degradation indicator simultaneously with the determinations of the usage quantity, the degradation indicator changing in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity, and

estimating, based upon a plurality of pairs of the measured degradation indicator and the determined usage quantity, the future usage quantity that indicates how much the rechargeable battery may be further used until the measured degradation indicator exceeds a predetermined level.

15. A battery diagnosing method for estimating a future usage quantity of a rechargeable battery, comprising:

determining a usage quantity that indicates how much the rechargeable battery has been used,

measuring a degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery, wherein the degradation indicator is measured independently from the usage quantity, and

estimating, based upon the pair of the measured degradation indicator and the determined usage quantity, and a standard relationship between the change in the degradation indicator and increase of the usage quantity, the future usage quantity that indicates how much the rechargeable battery can be further used until the degradation indicator exceeds a predetermined level.

16. A battery diagnosing method for determining whether a rechargeable battery is in an active state or a non-active state, comprising:

measuring a first degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery,

measuring a second degradation indicator that changes in accordance with progress of the degradation of the rechargeable battery,

determining whether the pair of the measured first degradation indicator and the measured second degradation indicator belongs in an active region or a non-active region within predetermined reference activity map, the reference activity map being a two-dimensional map whose axes are the first degradation indicator and the second degradation indicator and being divided into at least the active region and the non-active region.