Method and system for charging a vehicle battery

• US 8,793,042 B2
• Filed: 07/28/2011
• Issued: 07/29/2014
• 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: Gale, Allan Roy, Blakemore, Bruce Carvell, Elie, Larry Dean
• Primary Examiner(s): Badii, Behrang
• Assistant Examiner(s): GREENE, DANIEL LAWSON
• Application Number:
  US13/192,507
• Publication Number:
  US 20130026970A1
• Time in Patent Office: 1,097 Days
• Field of Search: 701/1, 701/22
• US Class Current: 701/22
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60W 10/00 Conjoint control of vehicle sub-units of different type or different function for propulsion of purely electrically-propelled vehicles with power supplied within the vehicle B60L50/00 - B60L58/00
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 2310/40 The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A vehicle power system includes a battery having a plurality of cells and at least one controller. The at least one controller causes the cells to acquire charge for a period of time such that at the expiration of the period of time, voltages of some of the cells are approximately equal to a specified voltage, amp·hours stored by other of the cells are approximately equal, and an amount of energy stored by the battery is at least equal to a predetermined target energy amount.

Claims

1. A vehicle comprising:

a battery including a plurality of cells; and

,

at least one controller configured to cause the cells to receive current for a period of time and, during the period of time, to cause one or more of the cells to supply cell load current such that at the expiration of the period of time, voltages of some of the cells are approximately equal to a specified voltage and amp·

hours stored by other of the cells are approximately equal to a specified amp·

hours, wherein voltages of at least some of the other of the cells are not approximately equal and wherein an amount of energy stored by the battery is at least equal to a predetermined target energy amount.

2. The vehicle of claim 1 further comprising an electric machine configured to transform electrical energy from the battery to mechanical energy to move the vehicle.

3. The vehicle of claim 1 wherein the specified voltage is a full rated cell voltage.

4. The vehicle of claim 1 wherein the at least one controller is further configured to determine, for each of the one or more of the cells, a duration of time to cause the cell to supply cell load current.

5. The vehicle of claim 4 wherein the steps of causing the cells to receive current for a period of time and, during the period of time, causing one or more of the cells to supply cell load current are performed if each of the durations of time is less than the period of time.

6. The vehicle of claim 4 wherein each of the durations of time to cause the cells to supply cell load current is based on an initial capacity of the corresponding cell.

7. A method for charging cells of a traction battery comprising:

charging some of the cells to a specified common target voltage; and

charging other of the cells to a predetermined common target capacity such that voltages of at least some of the other of the cells are not approximately equal and an amount of energy stored by the cells is at least equal to a predetermined target energy amount.

8. The method of claim 7 wherein the steps of charging some of the cells to a specified common target voltage and charging other of the cells to a predetermined common target capacity are performed concurrently.

9. The method of claim 7, wherein the steps of charging some of the cells to a specified common target voltage and charging other of the cells to a predetermined common target capacity are performed during a first period of time, further comprising charging the cells to a predetermined common target capacity prior to the first period of time.

10. The method of claim 7, wherein the steps of charging some of the cells to a specified common target voltage and charging other of the cells to a predetermined common target capacity are performed during a first period of time, further comprising charging the cells to a common voltage after the first period of time.

11. The method of claim 10 wherein the common voltage is approximately equal to a manufacturer'"'"'s suggested maximum cell voltage.

12. The method of claim 7 wherein the steps of charging some of the cells to a specified common target voltage and charging other of the cells to a predetermined common target capacity include causing each of one or more of the cells to supply cell load current for a different duration of time.

13. The method of claim 12 wherein the steps of charging some of the cells to a specified common target voltage and charging other of the cells to a predetermined common target capacity are performed if each of the durations of time is less than a battery total charge time.

14. A vehicle 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 at the expiration of the period of time, voltages of some of the cells are approximately equal to a specified voltage and amp·

hours stored by other of the cells are approximately equal to a specified amp·

hours, wherein voltages of at least some of the other of the cells are not approximately equal and wherein an amount of energy stored by the battery is at least equal to a predetermined target energy amount.

15. The system of claim 14 wherein the rates at which charge is acquired by the cells are different among at least some of the cells for at least a portion of the period of time.

16. The system of claim 15 wherein the at least one controller is further configured to cause the at least some of the cells to supply cell load current for the at least a portion of the period of time.

17. The system of claim 16 wherein the at least some of the cells supply cell load current for different durations of time.