Maximized battery capacity charge based on equilibrium charging

• US 9,048,679 B2
• Filed: 06/28/2012
• Issued: 06/02/2015
• Est. Priority Date: 06/28/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Patino, Joseph
• Primary Examiner(s): Siek, Vuthe
• Application Number:
  US13/535,921
• Publication Number:
  US 20140002007A1
• Time in Patent Office: 1,069 Days
• Field of Search: 320/107, 320/132, 320/157, 320/162
• US Class Current: 1/1
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

The present disclosure provides for repeatedly charging a rechargeable battery during a single charging session to a steady state voltage to attain a higher charge capacity of the rechargeable battery than a charge capacity of the rechargeable battery existing prior to the rechargeable battery being charged to the steady state voltage. The higher charge capacity is attained without exceeding a maximum allowable charge threshold of the rechargeable battery.

Claims

1. A method for charging a rechargeable battery, comprising:

a device supplying a charge current to the rechargeable battery until it is determined that a battery voltage of the rechargeable battery is equal to or greater than a first voltage threshold, wherein the first voltage threshold is an optimal charge threshold of the rechargeable battery;

the device pausing supplying the charge current;

determining that a resume charge condition is satisfied, wherein the resume charge condition is one or more of pausing supplying the charge current for a predetermined period of time and a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold;

the device resuming supplying the charge current to the rechargeable battery until it is determined that the battery voltage of the rechargeable battery is equal to or greater than the first voltage threshold, wherein the first voltage threshold is the optimal charge threshold of the rechargeable battery; and

the device repeating, during a single charging session, the pausing, determining and resuming, until a stop charge condition is satisfied, wherein the stop charge condition is one or more of performing the repeating a predetermined number of iterations, the battery voltage reaching a steady state voltage that is greater than or equal to an equilibrium voltage threshold of the battery, and a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold.

2. The method of claim 1, wherein the stop charge condition is the battery voltage reaching a steady state voltage that is greater than or equal to an equilibrium voltage threshold of the battery.

3. The method of claim 2, wherein the first voltage threshold is greater than an equilibrium voltage threshold of the battery.

4. The method of claim 2, wherein the steady state voltage is characterized by a voltage drop that is substantially determined based upon the optimal charge threshold of the rechargeable battery and an impedance of the rechargeable battery and is not associated with depletion of the rechargeable battery.

5. The method of claim 1, wherein the resume charge condition is pausing supplying the charge current for a predetermined period of time.

6. The method of claim 1, wherein the resume charge condition is a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold.

7. The method of claim 6, wherein the drop in the battery voltage occurs after a previous charging of the rechargeable battery and is not associated with depletion of the rechargeable battery.

8. The method of claim 1, wherein the resume charge condition is satisfied regardless of depletion of the rechargeable battery.

9. The method of claim 1, further comprising, prior to pausing supplying the charge current, tapering the charge current until the battery voltage is equal to or greater than a second voltage threshold, the second voltage threshold being greater than the first voltage threshold.

10. The method of claim 1, further comprising, during resuming supplying the charge current, tapering the charge current until the battery voltage is equal to or greater than a second voltage threshold, the second voltage threshold being greater than the first voltage threshold.

11. The method of claim 1, further comprising, during resuming supplying the charge current, gradually increasing the charge current from a minimum charge current until the battery voltage is equal to or greater than a second voltage threshold, the second voltage threshold being greater than the first voltage threshold.

12. A non-transitory computer-readable medium having computer-executable instructions for charging a rechargeable battery, comprising:

supplying a charge current to the rechargeable battery until it is determined that a battery voltage of the rechargeable battery is equal to or greater than a first voltage threshold, wherein the first voltage threshold is an optimal charge threshold of the rechargeable battery;

pausing supplying the charge current;

determining that a resume charge condition is satisfied, wherein the resume charge condition is one or more of pausing supplying the charge current for a predetermined period of time and a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold;

resuming supplying the charge current to the rechargeable battery until it is determined that the battery voltage of the rechargeable battery is equal to or greater than the first voltage threshold, wherein the first voltage threshold is the optimal charge threshold of the rechargeable battery; and

repeating, during a single charging session, the pausing, determining and resuming, until a stop charge condition is satisfied, wherein the stop charge condition is one or more of performing the repeating a predetermined number of iterations, the battery voltage reaching a steady state voltage that is greater than or equal to an equilibrium voltage threshold of the battery, and a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold.

13. The non-transitory computer-readable medium of claim 12, further comprising, prior to pausing supplying the charge current, tapering the charge current until the battery voltage is equal to or greater than a second voltage threshold, the second voltage threshold being greater than the first voltage threshold.

14. The non-transitory computer-readable medium of claim 12, further comprising, during resuming supplying the charge current, tapering the charge current until the battery voltage is equal to or greater than a second voltage threshold, the second voltage threshold being greater than the first voltage threshold.

15. The non-transitory computer-readable medium of claim 12, further comprising, during resuming supplying the charge current, gradually increasing the charge current from a minimum charge current until the battery voltage is equal to or greater than a second voltage threshold, the second voltage threshold being greater than the first voltage threshold.

16. A device for charging a rechargeable battery, comprising:

a voltage detector that detects a voltage across terminals of the rechargeable battery;

a switching device that controls application or interruption of a charge current to the rechargeable battery;

a charging controller coupled to the switching device and to the voltage detector that controls the switching device such that;

the charging controller controls the switching device to supply a charge current to the rechargeable battery until it is determined that a battery voltage of the rechargeable battery is equal to or greater than a first voltage threshold, wherein the first voltage threshold is an optimal charge threshold of the rechargeable battery;

the charging controller controls the switching device to pause supplying the charge current;

in response to determining that a resume charge condition is satisfied, the charging controller controls the switching device to resume supplying the charge current to the rechargeable battery until it is determined that the battery voltage of the rechargeable battery is equal to or greater than the first voltage threshold, wherein the first voltage threshold is the optimal charge threshold of the rechargeable battery and wherein the resume charge condition is one or more of pausing supplying the charge current for a predetermined period of time and a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold; and

repeating, during a single charging session, the pausing, determining and resuming, until a stop charge condition is satisfied, wherein the stop charge condition is one or more of performing the repeating a predetermined number of iterations, the battery voltage reaching a steady state voltage that is greater than or equal to an equilibrium voltage threshold of the battery, and a drop in the battery voltage of the rechargeable battery meeting or exceeding a voltage drop threshold.

17. The device of claim 16, the device further comprising a timer coupled to the charging controller and upon the timer reaching a predetermined time, the resume charge condition is satisfied and the charging controller controls the switching device to resume supplying the charge current to the rechargeable battery.

18. The device of claim 16, wherein the voltage detector measures the battery voltage of the rechargeable battery to determine there is a drop in the battery voltage that is not associated with depletion of the rechargeable battery and is equal to or greater than a voltage drop threshold the resume charge condition is satisfied, the charging controller controls the switching device to resume supplying the charge current to the rechargeable battery.

19. The device of claim 16, wherein the resume charge condition is satisfied following a previous charging of the rechargeable battery by the device during the single charging session.

20. The device of claim 16, wherein the stop charge condition is the battery voltage reaching a steady state voltage that is greater than or equal to a second voltage threshold that is an equilibrium voltage threshold.

21. The device of claim 20, wherein the first voltage threshold is greater than the second voltage threshold.

22. The device of claim 20, wherein the steady state voltage is characterized by a voltage drop that is substantially determined based upon the optimal charge threshold of the rechargeable battery and the impedance of the rechargeable battery and is not associated with depletion of the rechargeable battery.