Method for accurate battery run time estimation utilizing load-condition voltage

• US 20100138175A1
• Filed: 12/02/2008
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Yu, Huili
• Granted Patent: US 8,660,808 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/3835 involving only voltage measurements

Abstract

One disclosed embodiment is a method for accurately estimating a run time of a battery utilized by an electronic device. The method comprises determining a starting battery capacity utilizing an open-circuit voltage of the battery, determining a battery capacity decline rate utilizing a load-condition voltage of the battery, and determining a low-voltage-alarm battery capacity during an active operation of the electronic device. The method further comprises utilizing the starting battery capacity, the battery capacity decline rate, and the low-voltage-alarm battery capacity to estimate the run time of the battery. The run time estimate is determined, in one embodiment, by dividing the difference of the starting battery capacity and the low-voltage-alarm battery capacity by the battery capacity decline rate. One embodiment utilizes an open-circuit voltage lookup table, a load-condition voltage lookup table, and a low-voltage-alarm lookup table that are configured for use with a certain type of battery.

Claims

1. A method for accurately estimating a run time of a battery utilized by an electronic device, the method comprising:

determining a starting battery capacity utilizing an open-circuit voltage of said battery;

determining a battery capacity decline rate utilizing a load-condition voltage of said battery;

determining a low-voltage-alarm battery capacity during an active operation of said electronic device;

utilizing said starting battery capacity, said battery capacity decline rate, and said low-voltage-alarm battery capacity to estimate said run time of said battery.

2. The method of claim 1, wherein said starting battery capacity is determined by using an open-circuit voltage lookup table.

3. The method of claim 1, wherein said battery capacity decline rate is determined by utilizing a change in said load-condition voltage of said battery.

4. The method of claim 1, wherein said utilizing said load-condition voltage of said battery comprises retrieving a load-condition voltage change from a load-condition voltage lookup table.

5. The method of claim 1, wherein said utilizing said load-condition voltage of said battery comprises determining a load-condition voltage-change time.

6. The method of claim 5, wherein said determining said battery capacity decline rate comprises utilizing said load-condition voltage-change time and at least one previously determined voltage-change time.

7. The method of claim 1, wherein said low-voltage-alarm battery capacity is determined by using a low-voltage-alarm lookup table.

8. The method of claim 1, further comprising utilizing an open-circuit voltage lookup table, a load-condition voltage lookup table, and a low-voltage-alarm lookup table.

9. The method of claim 8, wherein said open-circuit voltage lookup table, said load-condition voltage lookup table, and said low-voltage-alarm lookup table are configured for use with a plurality of batteries.

10. The method of claim 1, wherein said utilizing said starting battery capacity, said battery capacity decline rate, and said low-voltage-alarm battery capacity comprises dividing a difference of said starting battery capacity and said low-voltage-alarm battery capacity by said battery capacity decline rate to estimate said run time of said battery.

11. The method of claim 1, wherein said battery is a lithium-ion battery.

12. The method of claim 1, wherein said battery is configured for use with an electronic device selected from the group consisting of a cellular telephone, a portable media player, a digital camera, and a portable electronic device.

13. The method of claim 1, wherein said active operation is selected from the group consisting of playing a song, playing a movie, making a cellular telephone call, and performing a long-duration activity.

14. The method of claim 1, further comprising displaying an estimate of said run time of said battery to a user.

15. A method for accurately estimating a run time of a battery utilized by an electronic device, the method comprising:

determining a starting battery capacity utilizing an open-circuit voltage of said battery;

determining a battery capacity decline rate utilizing a load-condition voltage of said battery;

determining a low-voltage-alarm battery capacity during an active operation of said electronic device;

dividing a difference of said starting battery capacity and said low-voltage-alarm battery capacity by said battery capacity decline rate to estimate said run time of said battery.

16. The method of claim 15, wherein said starting battery capacity is determined by using an open-circuit voltage lookup table.

17. The method of claim 15, wherein said utilizing said load-condition voltage of said battery comprises retrieving a load-condition voltage change from a load-condition voltage lookup table.

18. The method of claim 15, wherein said low-voltage-alarm battery capacity is determined by using a low-voltage-alarm lookup table.

19. The method of claim 15, wherein said battery is configured for use with an electronic device selected from the group consisting of a cellular telephone, a portable media player, a digital camera, and a portable electronic device.

20. The method of claim 15, wherein said active operation is selected from the group consisting of playing a song, playing a movie, making a cellular telephone call, and performing a long-duration activity.