Detection of the end-of-life for a rechargeable battery

• US 6,545,448 B1
• Filed: 12/18/2001
• Issued: 04/08/2003
• Est. Priority Date: 12/18/2001
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Stanley, Randy P., Silvester, Kelan Craig
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US10/025,263
• Time in Patent Office: 476 Days
• Field of Search: 324/436, 320/127, 320/132, 320/134, 320/136, 320/DIG.21
• US Class Current: 320/132
• CPC Class Codes: G01R 31/378 specially adapted for the type of battery or accumulator
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• 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 6/42 Grouping of primary cells into batteries H01M6/40 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for the detection of the end-of-life for a rechargeable battery. The method of one embodiment comprises identifying a rechargeable battery. A designed capacity of the rechargeable batterty is determined. A present full charge capacity of the rechargeable battery is determined. A status of the rechargeable battery is evaluated. An end-of-life warning for the battery is issued if an end-of-life status is detected.

Claims

1. A method comprising:

identifying a rechargeable battery;

determining a designed capacity of said rechargeable battery;

determining a present full charge capacity of said rechargeable battery;

evaluating a status of said rechargeable battery, said evaluating comprising calculating remaining capacity of said rechargeable battery as a percentage of said designed capacity, said percentage calculated as dividing said present full charge capacity by said designed capacity; and

issuing an end-of-life warning for said rechargeable battery if an end-of-life status is detected.

2. The method of claim 1 further comprising checking whether said rechargeable battery is a smart battery.

3. The method of claim 2 further comprising sending a request to said smart battery for battery information.

4. The method of claim 3 wherein said battery information comprises a serial number and battery type to uniquely identify a battery.

5. The method of claim 4 wherein said determining said designed capacity comprises requesting said designed capacity value from said smart battery.

6. The method of claim 1 further comprising saving said designed capacity, said present full charge capacity, and a unique identifier for said rechargeable battery to a record.

7. The method of claim 6 wherein said evaluating further comprises comparing said percentage against a threshold level, said threshold level defined as a capacity level below which said rechargeable battery is at its end-of-life.

8. The method of claim 7 further comprising:

checking a number of charge cycles that have been conducted on said rechargeable battery, and issuing a cycling warning if said number of charge cycles has exceeded a cycling threshold; and

performing a charge leakage calculation to determine whether said leakage from said rechargeable battery is not acceptable.

9. A method comprising:

checking whether said battery is a smart battery;

checking whether a battery is known;

loading a profile for said battery if said battery is known;

requesting battery information if said battery is not known, said requesting comprising sending information requests to said battery if said battery is smart and comprising querying a user for said battery information if said battery is not smart;

polling said battery for a present battery status;

evaluating said present battery status to determine whether said battery has reached an end-of-life condition; and

issuing a warning if said end-of-life condition exists.

10. The method of claim 9 wherein said checking comprises reading a unique identifier for said battery and comparing said identifier with a list of known batteries, said known batteries having stored records with battery characteristics.

11. The method of claim 10 wherein said battery information comprises a designed capacity for said battery and a battery technology type.

12. The method of claim 11 wherein said polling comprises querying said battery for a present full charge capacity if said battery is smart, and wherein said polling comprises measuring said full charge,capacity if said battery is not smart.

13. The method of claim 12 wherein said evaluating said present battery status comprises calculating a remaining life value for said battery as a percentage of said designed capacity, said remaining life value based on what percent of said designed capacity is represented by said present full charge capacity.

14. The method of claim 13 wherein said end-of-life condition is present if said remaining life value is below a threshold level, said threshold level defined as a battery capacity value above which said battery is capable of holding a sufficient amount of charge.

15. An apparatus comprising:

a rechargeable battery to provide stored charge from power cells;

a monitoring circuit coupled to said rechargeable battery, said monitoring circuit to measure voltages and currents across said rechargeable battery, said monitoring circuit further to determine a present full charge capacity in said rechargeable battery; and

a controller coupled to said monitoring circuit, said controller to detect a battery end-of-life condition in said rechargeable battery, wherein said controller is to calculate a remaining life value for said rechargeable battery as a percentage of a designed capacity for said rechargeable battery, said remaining life value based on what percent of said designed capacity is represented by said present full charge capacity.

16. The apparatus of claim 15 further comprising a display screen coupled to said controller, said display screen to provide a battery end-of-life warning upon detection of said end-of-life condition.

17. The apparatus of claim 16 wherein said controller evaluates a present battery status to determine whether said rechargeable battery has reached an end-of-life condition.

18. The apparatus of claim 17 wherein said end-of-life condition is present if said remaining life value is below a threshold level, said threshold level defined as a battery capacity value above which said rechargeable battery is capable of holding a sufficient amount of charge.

19. The apparatus of claim 18 further comprising a charger to recharge said rechargeable battery.

20. A machine readable medium having embodied thereon a computer program, said computer program being executable by a machine to perform a method comprising:

identifying a rechargeable battery;

determining a designed capacity of said rechargeable battery;

determining a present full charge capacity of said rechargeable battery;

evaluating a status of said rechargeable battery, said evaluating comprising calculating a remaining capacity of said rechargeable battery as a percentage of said designed capacity, said percentage calculated as dividing said present full charge capacity by said designed capacity; and

issuing an end-of-life warning for said battery if an end-of-life status is detected.

21. The machine readable medium of claim 20 wherein said evaluating further comprises comparing said percentage against a threshold level, said threshold level defined as capacity level below which said rechargeable battery is at its end-of-life.

22. The machine readable medium of claim 21 further comprising storing a first value indicating an amount of charge stored in said rechargeable battery upon shutdown.

23. The machine readable medium of claim 22 further comprising reading at startup said first value and a second value indicating an amount of charge stored in said rechargeable battery upon startup, and calculating a charge leakage value from said first and second values and time elapsed between said shutdown and startup.

24. The machine readable medium of claim 23 further comprising issuing a charge leakage warning if said charge leakage value is not acceptable.

25. The machine readable medium of claim 24 checking number of charge cycles that have been conducted on said rechargeable battery, and issuing a cycling warning if said number of charge cycles has exceeded a cycling threshold.