Battery cell capacity balancing system and method

• US 9,145,064 B2
• Filed: 07/28/2011
• Issued: 09/29/2015
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Blakemore, Bruce Carvell, Gale, Allan Roy, Elie, Larry Dean
• Primary Examiner(s): Badii, Behrang
• Assistant Examiner(s): Greene, Daniel L
• Application Number:
  US13/192,518
• Publication Number:
  US 20130030619A1
• Time in Patent Office: 1,524 Days
• Field of Search: 701/22, 320/128, 429/150
• US Class Current: 1/1
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A vehicle may include an electric machine that generates motive power for the vehicle, a plurality of cells that store energy for the electric machine, and at least one controller. The at least one controller may cause the cells to receive current for a period of time and, during the period of time, cause at least some of the cells to supply cell load current such that at the expiration of the period of time, the amount of energy stored by the cells is at least equal to a predetermined target energy level.

Claims

1. A vehicle comprising:

an electric machine configured to generate motive power for the vehicle;

a battery including a plurality of cells configured to store energy for the electric machine; and

at least one controller configured to cause the cells to receive current for a predetermined period of time and, during the predetermined period of time, to cause at least some of the cells to each also supply cell load current for a predetermined duration such that upon expiration of the predetermined period of time, an amount of Amp·

hours stored by each of the cells is approximately equal to a common target, wherein at least some of the predetermined durations are different.

2. The vehicle of claim 1 wherein, for each of the at least some of the cells, the predetermined duration is based on an initial Amp·

hours stored in the cell.

3. A method for charging cells of a battery comprising:

by a controller,

causing the cells to receive current for a predetermined period of time; and

during the predetermined period of time, causing at least some of the cells to each also supply cell load current for a predetermined duration such that upon expiration of the predetermined period of time, an Amp·

hours stored in each of the cells is approximately equal to a common target.

4. The method of claim 3 wherein the period of time is based on a difference between the common target and a minimum of initial Amp·

hours stored in each of the cells.

5. The method of claim 3 wherein each of the durations is based on an initial Amp·

hours stored in a corresponding cell.

6. The method of claim 3 wherein upon the expiration of the predetermined period of time, an amount of energy stored by the cells is at least equal to a predetermined target energy level.

7. A power system comprising:

a battery including a plurality of cells; and

at least one controller configured to cause the cells to acquire charge for a period of time such that upon expiration of the period of time, an amount of Amp·

hours stored by each of the cells is approximately equal to a predetermined common target.

8. The system of claim 7 wherein a rate at which charge is acquired by the cells is different among at least some of the cells for at least a portion of the period of time.

9. The system of claim 7 wherein the period of time is based on a difference between the common target and a minimum of initial Amp·

hours stored in each of the cells.

10. The system of claim 7 wherein upon the expiration of the period of time, an amount of energy stored by the cells is at least equal to a predetermined target energy level.