Mitigating premature wear out of a rechargeable battery

• US 9,263,912 B2
• Filed: 02/05/2013
• Issued: 02/16/2016
• Est. Priority Date: 02/05/2013
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Verdun, Gary Joseph, Thompson, Richard C.
• Primary Examiner(s): Chiang, Jack
• Assistant Examiner(s): Bowers, Brandon
• Application Number:
  US13/759,266
• Publication Number:
  US 20140217958A1
• Time in Patent Office: 1,106 Days
• Field of Search: 320/134, 320/107
• US Class Current: 1/1
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

A computer-implemented method and information handling system manage a rate of decreasing full capacity of a rechargeable battery by using a projected/target rate of decreasing charge capacity for the battery. The method includes determining an actual rate of decreasing charge capacity of the battery, comparing the actual rate of decreasing charge capacity to the projected/target rate of decreasing charge capacity to determine whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity, and if the actual rate of decreasing charge capacity is greater than the projected/target rate of decreasing charge capacity, modifying one or more variable parameters to slow down the actual rate of decreasing charge capacity of the battery such that the actual rate of decreasing charge capacity remains within a range of the projected/target rate of decreasing charge capacity, and charging and discharging the battery using the modified parameters.

Claims

1. A computer-implemented method of tracking and moderating a rate of battery wear out, the method comprising:

determining an actual rate of decreasing charge capacity of a rechargeable battery that exhibits a decreasing full charge capacity;

comparing the actual rate of decreasing charge capacity to a projected rate of decreasing charge capacity for the battery to determine whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity; and

if the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity, modifying one or more variable parameters to slow down the actual rate of decreasing charge capacity of the battery such that the actual rate of decreasing charge capacity remains within a range of the projected rate of decreasing charge capacity, wherein;

assigned values of the one or more variable parameters affect the rate of decreasing charge capacity; and

modifying the one or more variable parameters includes changing a value of at least one variable parameter to provide updated parameter values and reducing a fast charge current and a termination voltage used to charge the rechargeable battery in order to decrease the temperature induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to temperature induced stress; and

charging and discharging the battery utilizing the updated parameter values of the at least one variable parameter.

2. The computer-implemented method of claim 1, wherein modifying the one or more variable parameters includes determining whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to at least one of voltage induced stress, charging current induced stress, discharging current induced stress, and temperature induced stress.

3. The computer-implemented method of claim 1, wherein modifying the one or more variable parameters includes reducing a termination voltage used when charging the rechargeable battery in order to decrease the voltage induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to voltage induced stress.

4. The computer-implemented method of claim 1, wherein modifying the one or more variable parameters includes reducing a fast charge current used to charge the rechargeable battery in order to decrease the current induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to charging current induced stress.

5. The computer-implemented method of claim 4, wherein modifying the one or more variable parameters further comprises reducing a termination voltage used to charge the rechargeable battery.

6. The computer-implemented method of claim 4, wherein modifying the one or more variable parameters includes reducing a processor maximum operating frequency to decrease the discharging current induced stress on the battery.

7. The computer-implemented method of claim 1, wherein modifying the one or more variable parameters further includes modifying cooling system settings to provide higher fan speeds to further decrease the temperature induced stress on the battery.

8. The computer-implemented method of claim 1, wherein modifying the one or more variable parameters further includes modifying system power settings to modulate processor frequencies to further decrease the temperature induced stress on the battery.

9. The computer-implemented method of claim 1, wherein determining an actual rate of decreasing charge capacity of the battery includes:

periodically collecting battery usage data, including system operating data that affects a charge capacity of the battery; and

sending the collected battery usage data to a computer system for analysis to determine, from the collected battery usage data, conditions that prematurely age the rechargeable battery.

10. An information handling system comprising:

a battery management unit having an embedded controller;

a rechargeable battery having a decreasing full charge capacity;

a charger;

a computer-readable storage device embodying computer program instructions executable by a processor and configured to cause the battery management unit to;

determine an actual rate of decreasing charge capacity of the battery;

compare the actual rate of decreasing charge capacity to the projected rate of decreasing charge capacity to determine whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity;

if the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity, modify one or more variable parameters to slow down the actual rate of decreasing charge capacity of the battery such that the actual rate of decreasing charge capacity remains within a range of the projected rate of decreasing charge capacity with each repeated charge and discharge;

wherein;

assigned values of the one or more variable parameters affect the rate of decreasing charge capacity; and

modifying the one or more variable parameters includes changing a value of at least one variable parameter to provide updated parameter values;

wherein, in response to the actual rate of decreasing charge capacity being greater than the projected rate of decreasing charge capacity due to discharging current induced stress, the BMU modifying the one or more variable parameters further includes the BMU reducing at least one of;

a processor maximum operating frequency to decrease the current induced stress on the battery; and

a number of concurrently executing applications supported; and

charge and discharge the rechargeable battery using the modified one or more variable parameters.

11. The information handling system of claim 10, wherein to modify the one or more variable parameters, the BMU:

determines whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to voltage induced stress, charging current induced stress, discharging current induced stress, or temperature induced stress;

reduces a termination voltage used when charging the rechargeable battery in order to decrease the voltage induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to voltage induced stress; and

reduces a fast charge current used to charge the rechargeable battery in order to decrease the current induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to charging current induced stress.

12. The information handling system of claim 10, wherein to modify the one or more variable parameters, the BMU reduces a fast charge current and a termination voltage used to charge the rechargeable battery in order to decrease the temperature induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to temperature induced stress.

13. The information handling system of claim 12, wherein the BMU further modifies at least one of:

cooling system settings to use higher fan speeds to further decrease the temperature induced stress on the battery; and

system power settings to modulate processor frequencies to further decrease the temperature induced stress on the battery.

14. The information handling system of claim 10, wherein to determine an actual rate of decreasing charge capacity of the battery, the BMU:

periodically collects battery usage data, including system operating data; and

sends the collected battery usage data to a remote computer system for analysis to determine, from the collected battery usage data, conditions that prematurely age the rechargeable battery.

15. A computer-readable storage device embodying computer program code, the computer program code comprising computer executable instructions configured for:

determining an actual rate of decreasing charge capacity of a rechargeable battery that exhibits a decreasing full charge capacity;

comparing the actual rate of decreasing charge capacity to a projected rate of decreasing charge capacity for the battery to determine whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity;

if the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity, modifying one or more variable parameters to slow down the actual rate of decreasing charge capacity of the battery such that the actual rate of decreasing charge capacity remains within a range of the projected rate of decreasing charge capacity, wherein modifying the one or more variable parameters includes determining whether the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to voltage induced stress, charging current induced stress, discharging current induced stress, or temperature induced stress;

wherein assigned values of the one or more variable parameters affect the rate of decreasing charge capacity and modifying the one or more variable parameters includes changing a value of at least one variable parameter to provide updated parameter values;

reducing a termination voltage used when charging the rechargeable battery in order to decrease the voltage induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to voltage induced stress;

reducing a fast charge current used to charge the rechargeable battery in order to decrease the current induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to current induced stress; and

charging and discharging the battery utilizing the updated parameter values of the at least one variable parameter.

16. The computer-readable storage device of claim 15, wherein the computer executable instructions for modifying the one or more variable parameters due to discharging current induced stress further comprises computer executable instructions configured for:

reducing at least one of a processor maximum operating frequency and a number of concurrently operating secondary devices to decrease the discharging current induced stress on the battery.

17. The computer-readable storage device of claim 15, wherein the computer executable instructions for modifying the one or more variable parameters comprises instructions configured for reducing a current fast charge and a termination voltage used to charge the rechargeable battery in order to decrease the temperature induced stress on the battery when the actual rate of decreasing charge capacity is greater than the projected rate of decreasing charge capacity due to temperature induced stress.

18. The computer-readable storage device of claim 15, wherein the computer executable instructions for modifying the one or more variable parameters comprises instructions configured for modifying at least one of:

cooling system settings to use higher fan speeds to further decrease the temperature induced stress on the battery; and

system power settings to modulate processor frequencies to further decrease the temperature induced stress on the battery.

19. The computer-readable storage device of claim 15, wherein the computer executable instructions for determining an actual rate of decreasing charge capacity of the battery includes instructions configured for:

periodically collecting battery data, including system operating conditions; and

sending the collected battery data to a remote computer system for analysis to determine operating conditions that prematurely age the rechargeable battery.