SYSTEMS AND METHODS FOR PERFORMING CELL BALANCING IN A VEHICLE USING CELL CAPACITIES

• US 20130043840A1
• Filed: 08/16/2011
• Published: 02/21/2013
• Est. Priority Date: 08/16/2011
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Herrmann, Matthew A., Bylsma, Zachary D.
• Application Number:
  US13/210,636
• Publication Number:
  US 20130043840A1
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• 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 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• 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

Systems and methods to perform cell balancing on a vehicle battery pack. Cell balancing regulates which cells are discharged during use of the battery pack. Individual cell capacities may be used to determine for how long individual cells are discharged.

Claims

1. A method for performing cell balancing on a vehicle battery pack having a plurality of cells comprising:

calculating or receiving, by one or more processors, an average cell capacity for the plurality of cells;

determining the difference between the cell capacity of an individual cell and the average cell capacity;

using the difference to determine a discharge timer value for a balancing gate that regulates the flow of current from the individual cell; and

controlling the balancing gate to discharge the individual cell based on the determined discharge timer value.

2. The method of claim 1, wherein the discharge timer value is determined using:

3. The method of claim 1, further comprising providing the discharge timer value to a display.

4. The method of claim 1, further comprising using the discharged energy from the cell to propel the vehicle.

5. The method of claim 1, further comprising using the discharged energy to power electronics in the vehicle.

6. The method of claim 1, further comprising:

storing, in a memory, a history of discharge timer values.

7. A controller for performing cell balancing on a vehicle battery pack having a plurality of cells, said controller comprising:

one or more processors, and

a memory coupled to the one or more processors, wherein the memory

stores executable instructions that, when executed by the one or more

processors, cause the one or more processors to;

calculate or receive an average cell capacity for the plurality of cells;

determine the difference between the cell capacity of an individual cell and the average cell capacity;

use the difference to determine a discharge timer value for a balancing gate that regulates the flow of current from the individual cell; and

generate a control command that causes the balancing gate to discharge the individual cell for an amount of time corresponding to the determined discharge timer value.

8. The controller of claim 7, wherein the discharge timer value is determined using:

9. The controller of claim 7, wherein the instructions further cause the one or more processors to provide the discharge timer value to a display.

10. The controller of claim 7, wherein the instructions further cause the one or more processors to determine that energy is needed to propel the vehicle and to generate the control command in response to a determination that energy is needed to propel the vehicle.

11. The controller of claim 7, wherein the instructions further cause the one or more processors to determine that energy is needed to power electronics in the vehicle and to generate the control command in response to a determination that energy is needed to power electronics in the vehicle.

12. The controller of claim 7, wherein the instructions further cause the one or more processors to store a history of discharge timer values in the memory.

13. The controller of claim 12, wherein the instructions further cause the one or more processors to provide the history of discharge timer values to an electronic device located outside of the vehicle.

14. The controller of claim 13, wherein the electronic device is a handheld device.

15. A system for performing cell balancing in a vehicle comprising:

voltage sensors configured to measure the voltage of a battery pack and a plurality of cells within said pack;

current sensors configured to measure the currents into and out of the pack; and

a processing circuit comprising;

an interface that receives voltage data from the voltage sensors and current data from the current sensors;

one or more processors; and

a memory coupled to the one or more processors, wherein the memory stores executable instructions that, when executed by the one or more processors, cause the one or more processors to;

calculate an average cell capacity for the plurality of cells using the voltage or current data;

calculate a cell capacity of an individual cell;

determine the difference between the cell capacity of the individual cell and the average cell capacity;

use the difference to determine a discharge timer value for a balancing gate that regulates the flow of current from the individual cell; and

generate a control command that causes the balancing gate to discharge the individual cell for an amount of time corresponding to the determined discharge timer value.

16. The system of claim 15, wherein the discharge timer value is determined using:

17. The system of claim 15 further comprising a cell balancing controller that provides control over the opening and closing of the balancing gate, wherein processing circuit provides the control command to the cell balancing controller, and wherein the cell balancing controller opens or closes the balancing gate in response to receiving the control command.

18. The system of claim 15, wherein the control command comprises a voltage that opens or closes the balancing gate.

19. The system of claim 15, wherein the instructions further cause the one or more processors to store a history of discharge timer values in the memory.

20. The system of claim 19, wherein the instructions further cause the one or more processors to provide the history of discharge timer values to an electronic device located outside of the vehicle.