MANAGEMENT OF HIGH-VOLTAGE LITHIUM-POLYMER BATTERIES IN PORTABLE ELECTRONIC DEVICES

• US 20150102767A1
• Filed: 09/23/2014
• Published: 04/16/2015
• Est. Priority Date: 08/25/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Dai, Hongli, Mank, Richard M.
• Granted Patent: US 9,450,443 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

The disclosed embodiments provide a system that manages use of a battery corresponding to a high-voltage lithium-polymer battery in a portable electronic device. During operation, the system monitors a cycle number of the battery during use of the battery with the portable electronic device, wherein the cycle number corresponds to a number of charge-discharge cycles of the battery. If the cycle number exceeds one or more cycle number thresholds, the system modifies a charging technique for the battery to manage swelling in the battery and use of the battery with the portable electronic device.

Claims

1-6. -6. (canceled)

7. A method, comprising:

by the portable electronic device, performing operations for;

monitoring a cycle number of a battery during use of the battery, the cycle number representing a number of charge-discharge cycles of the battery;

monitoring a temperature of the battery during use of the battery;

determining a charge voltage for the battery by;

when the temperature exceeds a temperature threshold, calculating the charge voltage by incrementally reducing a charge voltage based on a first cycle number threshold; and

when the temperature does not exceed the temperature threshold, calculating the charge voltage by incrementally reducing the charge voltage based on a second cycle number threshold, wherein the first cycle number threshold is different than the second cycle number threshold; and

modifying a charging technique for the battery to charge the battery at the charge voltage.

8. The method of claim 7, wherein incrementally reducing the charge voltage comprises reducing the charge voltage by a voltage in a range of 10 mV to 50 mV each time that the cycle number exceeds the corresponding first cycle number threshold or second cycle number threshold.

9. The method of claim 8, wherein the charge voltage is initially a voltage value in a range of 4.2V to 5V.

10. The method of claim 8, wherein reducing the charge voltage comprises reducing the charge voltage by a first voltage based on the first cycle number threshold and reducing the charge voltage by a second voltage based on the second cycle number threshold, wherein the first voltage is different than the second voltage.

11. The method of claim 7, further comprising:

monitoring a state-of-charge of the battery while charging the battery;

when the battery remains in a fully charged state for longer than a threshold time, halting charging the battery; and

when the state-of-charge of the battery falls below a threshold state-of-charge due to the battery self discharging, resuming charging the battery.

12. The method of claim 7, wherein the second cycle number threshold is higher than the first cycle number threshold.

13. An electronic device, comprising:

a controller; and

a monitoring mechanism;

wherein the controller and the monitoring mechanism perform operations for;

monitoring a cycle number of a battery during use of the battery, the cycle number representing a number of charge-discharge cycles of the battery;

monitoring a temperature of the battery during use of the battery;

determining a charge voltage for the battery by;

when the temperature exceeds a temperature threshold, calculating the charge voltage by incrementally reducing a charge voltage based on a first cycle number threshold; and

when the temperature does not exceed the temperature threshold, calculating the charge voltage by incrementally reducing the charge voltage based on a second cycle number threshold, wherein the first cycle number threshold is different than the second cycle number threshold; and

modifying a charging technique for the battery to charge the battery at the charge voltage.

14. The electronic device of claim 13, wherein incrementally reducing the charge voltage comprises reducing the charge voltage by a voltage in a range of 10 mV to 50 mV each time that the cycle number exceeds the corresponding first cycle number threshold or second cycle number threshold.

15. The electronic device of claim 14, wherein reducing the charge voltage comprises reducing the charge voltage by a first voltage based on the first cycle number threshold and reducing the charge voltage by a second voltage based on the second cycle number threshold, wherein the first voltage is different than the second voltage.

16. The electronic device of claim 13, wherein the controller and the monitoring mechanism further perform operations for:

monitoring a state-of-charge of the battery while charging the battery;

when the battery remains in a fully charged state for longer than a threshold time, halting charging the battery; and

when the state-of-charge of the battery falls below a threshold state-of-charge due to the battery self discharging, resuming charging the battery.

17. A non-transitory computer-readable storage medium storing instructions that, when executed by a controller, cause the controller to perform a method comprising:

monitoring a cycle number of a battery during use of the battery, the cycle number representing a number of charge-discharge cycles of the battery;

monitoring a temperature of the battery during use of the battery;

determining a charge voltage for the battery by;

when the temperature exceeds a temperature threshold, calculating the charge voltage by incrementally reducing a charge voltage based on a first cycle number threshold; and

when the temperature does not exceed the temperature threshold, calculating the charge voltage by incrementally reducing the charge voltage based on a second cycle number threshold, wherein the first cycle number threshold is different than the second cycle number threshold; and

modifying a charging technique for the battery to charge the battery at the charge voltage.

18. The computer-readable storage medium of claim 17, wherein incrementally reducing the charge voltage comprises reducing the charge voltage by a voltage in a range of 10 mV to 50 mV each time that the cycle number exceeds the corresponding first cycle number threshold or second cycle number threshold.

19. The computer-readable storage medium of claim 18, wherein reducing the charge voltage comprises reducing the charge voltage by a first voltage based on the first cycle number threshold and reducing the charge voltage by a second voltage based on the second cycle number threshold, wherein the first voltage is different than the second voltage.

20. The computer-readable storage medium of claim 17, wherein the method further comprises:

monitoring a state-of-charge of the battery while charging the battery;

when the battery remains in a fully charged state for longer than a threshold time, halting charging the battery; and

when the state-of-charge of the battery falls below a threshold state-of-charge due to the battery self discharging, resuming charging the battery.