Extending battery life for a rechargeable battery

Patent metadata

Field	Value
Publication number	US-9425630-B2
Application number	US-201114344031-A
Country	US
Kind code	B2
Filing date	Sep 8, 2011
Priority date	Sep 8, 2011
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

Technology is described for extending battery life for a rechargeable battery. The method can include estimating a desired energy storage for the rechargeable battery in an electronic device during an operating time period. Expected active periods for the rechargeable battery can be determined. A defined charge voltage can be computed based on the desired energy storage and expected active periods of the rechargeable battery in the electronic device. In addition, the rechargeable battery can be charged to the defined charge voltage.

First claim

The invention claimed is:

1. A method for extending battery life for a rechargeable battery, comprising:
determining, using a processor, an amount of energy expected to be used during an operating time period based on expected active periods for the rechargeable battery during the operating time period;
estimating, using the processor, a desired energy storage for the rechargeable battery based on the amount of energy expected to be used;
computing, using the processor, a defined charge voltage based on the desired energy storage; and
charging the rechargeable battery to the defined charge voltage.

2. The method as in claim 1 , further comprising computing an estimated temperature exposure over the operating time period of the rechargeable battery to use in calculating the defined charge voltage for the rechargeable battery.

3. The method as in claim 2 , further comprising applying a correction factor for an actual battery cell temperature when computing the defined charge voltage.

4. The method as in claim 1 , further comprising determining the expected active periods based on a history of the rechargeable battery.

5. The method as in claim 1 , further comprising taking into account the historical self-discharge of the rechargeable battery to determine the defined charge voltage.

6. The method as in claim 1 , further comprising using a power profile for the electronic device to determine the defined charge voltage.

7. The method as in claim 1 , further comprising defining a dormant time for the rechargeable battery to determine the defined charge voltage.

8. The method as in claim 1 , further comprising using a database to store historical battery attributes used for finding the defined charge voltage.

9. The method as in claim 8 , further comprising using the database to store a last capacity of the rechargeable battery.

10. The method as in claim 8 , further comprising using the database to record an average rechargeable battery temperature during use of the rechargeable battery in order to update temperature and capacity loss models.

11. The method as in claim 1 , further comprising tuning a target end-of-discharge voltage to increase battery lifetime.

12. A method for extending battery life of a rechargeable battery, comprising:
obtaining, using a processor, a discharge curve for the rechargeable battery;
obtaining, using the processor, a maximum allowed charge voltage for the rechargeable battery and a minimum end-of-discharge voltage using the discharge curve;
computationally reducing, using the processor, a charge voltage iteratively to find a minimum charge voltage that would provide sufficient energy for a projected use of the rechargeable battery in an electronic device;
computationally increasing, using the processor, the end-of-discharge voltage iteratively while keeping the charge voltage at a maximum allowed charge voltage to find a maximum end-of-discharge voltage that would provide sufficient energy for the projected use;
setting, using the processor, the charge voltage and target end-of-discharge voltage by computationally increasing the charge voltage from the minimum charge voltage or decreasing the end-of-discharge voltage from the maximum end-of-discharge voltage until the charge voltage and the end-of-discharge voltage would provide sufficient energy for the projected use; and
charging the rechargeable battery to the charge voltage.

13. The method as in claim 12 , further comprising defining the charge voltage based on a history of the rechargeable battery.

14. The method as in claim 12 , further comprising defining the charge voltage based on computing a temperature exposure of the rechargeable battery during an operating time period.

15. The method as in claim 12 , further comprising defining the charge voltage based on determining expected active and dormant periods for the rechargeable battery.

16. The method as in claim 12 , further comprising defining the charge voltage based on an estimated future average air temperature over an operating time period.

17. The method as in claim 12 , further comprising applying a correction factor for an actual battery cell temperature.

18. The method as in claim 12 , further comprising taking into account a historical self discharge of the rechargeable battery, a power profile for the electronic device, a last capacity of the rechargeable battery, or an average rechargeable battery temperature expected during use of the rechargeable battery.

19. A system for extending battery life for a rechargeable battery, comprising:
a database to store historical battery attribute data;
a capacity loss module to determine capacity loss of the rechargeable battery over time;
a total active time module to record active use time for the rechargeable battery;
a charging computation module to:
determine an anticipated future energy usage based on the active use time;
compute a charging voltage based on the historical battery attribute data, the capacity loss, and the anticipated future energy usage; and

a charging module to re-charge the rechargeable battery at the computed charging voltage.

20. The system as in claim 19 , further comprising electronic device sensors to record battery energy used, battery temperature, and battery sleep time for recording in the database.

Assignees

• Banerjee Neel
• Clarkson Anton Nicholas
• Mabeck Jeffrey Todd
• Hewlett Packard Development Co Lp

Inventors

• Banerjee Neel
• Clarkson Anton Nicholas
• Mabeck Jeffrey Todd

Classifications

• H01M10/42 Primary

  Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells (H01M10/60 takes precedence) · CPC title

• H02J7/00 Primary

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title

• H02J7/875

  Charging or discharging for charge maintenance, battery initiation or rejuvenation · CPC title

• H01M10/48

  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 title

• H02J7/0057

  Electricity · mapped topic