Battery state of charge reset

• US 8,427,109 B2
• Filed: 12/13/2005
• Issued: 04/23/2013
• Est. Priority Date: 04/06/2004
• Status: Expired due to Fees

• Current Assignee: Chevron Technology Ventures LLC (Chevron Corp.)
• Original Assignee: Chevron Technology Ventures LLC (Chevron Corp.)
• Inventors: Melichar, Robert J.
• Primary Examiner(s): RAMADAN, RAMY O
• Application Number:
  US11/301,750
• Publication Number:
  US 20060091861A1
• Time in Patent Office: 2,688 Days
• Field of Search: 320/104, 320/132, 320/133, 320/134
• US Class Current: 320/132
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/379 for lead-acid batteries
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A battery control module is provided for use with a battery and includes a voltage measuring module that measures battery voltage, a current measuring module that measures battery current, and a state of charge (SOC) module. The SOC module communicates with the current and voltage measuring modules, determines a reset voltage based on the battery current, compares the battery voltage and the reset voltage, and resets a battery SOC based on an outcome of the comparison.

Claims

1. A battery control module for use with a battery, comprising:

a voltage measuring module that measures battery voltage;

a current measuring module that measures battery current; and

a state of charge (SOC) module configured to communicate with said current and voltage measuring modules, determine low and high reset voltages based on said battery current and respective low and high polarization voltage limits of said battery, wherein said high reset voltage is greater than said low reset voltage, compare said battery voltage and said low and high reset voltages, reset a battery SOC using said low reset voltage if said battery voltage is less than said low reset voltage, and reset said battery SOC using said high reset voltage if said battery voltage is greater than said high reset voltage.

2. The battery control module of claim 1 wherein said SOC module determines said polarization voltage based on a time constant.

3. The battery control module of claim 2 wherein said time constant is based on a magnitude of said battery current.

4. The battery control module of claim 2 wherein said time constant is based on a direction of said battery current.

5. The battery control module of claim 2 wherein said time constant is based on a previous value of said polarization voltage.

6. The battery control module of claim 1 wherein said SOC module resets said battery SOC further based on whether a magnitude of said battery current exceeds a predetermined threshold.

7. A method for resetting an estimated battery SOC, comprising:

measuring a battery voltage;

measuring a battery current;

determining a low reset voltage and a high reset voltage based on said battery current and respective low and high polarization voltage limits of said battery;

comparing said battery voltage with said low and high reset voltages;

resetting said battery SOC using said low reset voltage if said battery voltage is less than said low reset voltage; and

resetting said battery SOC using said high reset voltage if said battery voltage is greater than said high reset voltage.

8. The method of claim 7

wherein said comparing step comprises at least one of a first comparison between said battery voltage and said low reset voltage and a second comparison between said battery voltage and said high reset voltage.

9. The method of claim 7 further comprising:

accumulating charge swing while charging said battery;

identifying a charge event based on said charge swing; and

resetting said battery SOC based on the outcome of said comparing step and an outcome of said identifying step.

10. The method of claim 7 further comprising:

accumulating discharge swing while discharging said battery;

identifying a discharge event based on said discharge swing; and

resetting said battery SOC based on the outcome of said comparing step and an outcome of said identifying step.

11. The method of claim 8 further comprising resetting said battery SOC to a reset battery SOC that is based on at least one of said low reset voltage and said high reset voltage.

12. The method of claim 7 wherein said polarization voltage is based on a time constant.

13. The method of claim 12 wherein said time constant is based on a magnitude of said battery current.

14. The method of claim 12 wherein said time constant is based on a direction of said battery current.

15. The method of claim 12 wherein said time constant is based on a previous value of said polarization voltage.