System and method for calibrating battery state of charge

Patent metadata

Field	Value
Publication number	US-2016101708-A1
Application number	US-201414510306-A
Country	US
Kind code	A1
Filing date	Oct 9, 2014
Priority date	Oct 9, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

The present disclosure is directed to a system and method for calibrating state-of-charge (SOC) of an energy storage device. The method includes monitoring, via a battery management system, at least one of an accumulated capacity of the energy storage device after a first SOC calibration or a time period after the first SOC calibration. Another step includes determining, via the battery management system, whether at least one of the accumulated capacity or the time period is above a predetermined threshold. If at least one of the accumulated capacity or the time period is above a predetermined threshold, then the method includes charging, via the battery management system, the energy storage device for a specified duration until the energy storage device reaches a second SOC calibration.

First claim

What is claimed is:

1 . A method for calibrating state-of-charge (SOC) of an energy storage device, the method comprising:
monitoring, via a battery management system, at least one of an accumulated capacity of the energy storage device after a first SOC calibration or a time period after the first SOC calibration; determining, via the battery management system, whether at least one of the accumulated capacity or the time period is above a predetermined threshold; and if at least one of the accumulated capacity or the time period is above a predetermined threshold, charging, via the battery management system, the energy storage device for a specified duration until the energy storage device reaches a second SOC calibration.

2 . The method of claim 1 , wherein the first SOC calibration comprises a top-of-charge (TOC) reset and the second calibration comprises a TOC reset.

3 . The method of claim 2 , wherein the TOC reset comprises setting the SOC of the energy storage device to 100% full capacity during recharge when a certain battery condition is reached.

4 . The method of claim 3 , wherein the battery condition comprises at least one of a current, a resistance, or a voltage of the energy storage device.

5 . The method of claim 1 , further comprising monitoring the accumulated capacity by monitoring a total ampere-hours discharged by the energy storage device after the first SOC calibration.

6 . The method of claim 1 , further comprising monitoring the time period after the first SOC calibration via one or more sensors, wherein the one or more sensors comprise at least one of a clock, a timer, or a counter.

7 . The method of claim 1 , wherein the predetermined threshold comprises a value greater than at least one of a rated capacity of the energy storage device or a time value that is indicative of a failure of the energy storage device to reach a SOC calibration.

8 . The method of claim 1 , wherein the SOC of the energy storage device comprises a percentage of a full capacity of the energy storage device that is available for discharge.

9 . The method of claim 1 , wherein the energy storage device comprises at least one of a lithium ion battery, a sodium nickel chloride battery, a sodium sulfur battery, a nickel metal hydride battery, a nickel cadmium battery, or a fuel cell.

10 . The method of claim 1 , wherein the energy storage device and the battery management system are components of an electric vehicle.

11 . A system for calibrating state-of-charge (SOC) of an energy storage device, the system comprising:
one or more sensors configured to monitor at least one of an accumulated capacity of the energy storage device after a first SOC calibration or a time period after the first SOC calibration; and a controller configured to perform one or more operations, the one or more operations comprising: determining whether at least one of the accumulated capacity or the time period is above a predetermined threshold; and if at least one of the accumulated capacity or the time period is above the predetermined threshold, charging the energy storage device for a specified duration until the energy storage device reaches a second SOC calibration.

12 . The method of claim 11 , wherein the first SOC calibration comprises a top-of-charge (TOC) reset and the second calibration comprises a TOC reset.

13 . The method of claim 12 , wherein the TOC reset comprises setting the SOC of the energy storage device to 100% full capacity during recharge when a certain battery condition is reached.

14 . The method of claim 13 , wherein the battery condition comprises at least one of a current, a resistance, or a voltage of the energy storage device.

15 . The system of claim 11 , wherein the accumulated capacity is based on a total ampere-hours discharged by the energy storage device after the first SOC calibration.

16 . The system of claim 11 , further comprising monitoring the time period after the first SOC calibration via one or more sensors, wherein the one or more sensors comprise at least one of a clock, a timer, or a counter.

17 . The system of claim 11 , wherein the predetermined threshold comprises a value greater than at least one of a rated capacity of the energy storage device or a time value that is indicative of a failure of the energy storage device to reach a SOC calibration.

18 . The system of claim 11 , wherein the energy storage device comprises at least one of a lithium ion battery, a sodium nickel chloride battery, a sodium sulfur battery, a nickel metal hydride battery, a nickel cadmium battery, or a fuel cell.

19 . A battery management system for an electric vehicle, the battery management system comprising:
a controller configured to perform one or more operations so as to calibrate a state-of-charge (SOC) of a battery, the one or more operations comprising: determining whether at least one of an accumulated capacity of the battery after a first top-of-charge (TOC) reset or the time period after the first TOC reset is above a predetermined threshold; and if at least one of the accumulated capacity or the time period is above the predetermined threshold, charging the battery for a specified duration until the battery reaches a second top-of-charge (TOC) reset.

20 . The battery management system of claim 19 , further comprising one or more sensors configured to:
monitor a total ampere-hours discharged by the battery after the first TOC reset so as to determine the accumulated capacity; and, monitor the time period after the first TOC reset.

Assignees

• Gen Electric

Inventors

• Zhang Jiucai
• Hicks Jr Charles Clarence
• Liu Sam T
• Kaucic Robert A
• Mao Leng

Classifications

• H02J7/60

  including safety or protection arrangements · CPC title

• H02J7/825

  Detection of fully charged condition · CPC title

• Y02T90/14

  Plug-in electric vehicles · CPC title

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• B60L11/1809

  Operations & Transport · mapped topic