Method for Determining the End-of-Discharge Threshold of a Rechargeable Battery

• US 20100060236A1
• Filed: 12/04/2007
• Published: 03/11/2010
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Perrin, Marion, Delaille, Arnaud
• Granted Patent: US 8,536,836 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The method for determining the end-of-discharge voltage threshold of a rechargeable battery comprises discharging the battery up to a predefined end-of-discharge voltage threshold, at least partial charging of the battery, determining, during said charging, an electrical parameter representative of a coup de fouet effect on charging, comparing said parameter with a predetermined characteristic and updating, if necessary, the end-of-discharge voltage threshold to be used for subsequent discharging according to the result of said comparison.

Claims

1-11. -11. (canceled)

12. A method for determining the end-of-discharge voltage threshold of a rechargeable battery, comprising the following set of successive steps:

discharging the battery up to a predefined end-of-discharge voltage threshold,

at least partial charging of the battery,

determining an electrical parameter representative of a coup de fouet effect on charging, at the beginning of said charging,

comparing said parameter with a predetermined characteristic constituted by a threshold value or a range of values,

updating the end-of-discharge voltage threshold to be used for subsequent discharging, according to the result of said comparison.

13. The method according to claim 12, wherein the parameter is representative of the difference between the peak voltage and the plateau voltage of the coup de fouet effect on charging.

14. The method according to claim 12, wherein the predetermined characteristic is constituted by a range of values, updating of the end-of-discharge voltage threshold consisting in:

raising the end-of-discharge voltage threshold by a predetermined first value when the parameter is greater than said range of values,

lowering the end-of-discharge voltage threshold by a predetermined second value when the parameter is lower than said range of values.

15. The method according to claim 14, wherein the range of values is comprised between 25 mV and 35 mV.

16. The method according to claim 14, wherein the predetermined first value is equal to 10 mV.

17. The method according to claim 14, wherein the predetermined second value is equal to 10 mV.

18. The method according to claim 12, wherein, the rechargeable battery being a battery of a new type, said method is used for determining the initial end-of-discharge voltage threshold to be used initially when using a battery of this type, and wherein the predetermined characteristic is constituted by a single threshold value, said method consisting in:

performing said set of successive steps at least once with a predefined first end-of-discharge voltage threshold until the electrical parameter representative of a coup de fouet effect on charging is lower than said single threshold value, in each set of successive steps updating of the first end-of-discharge voltage threshold consisting in raising said first end-of-discharge voltage threshold by a predetermined third value if the parameter is greater than or equal to the threshold value,

performing said set of successive steps at least once with a predefined second end-of-discharge voltage threshold until the electrical parameter representative of a coup de fouet effect on charging is greater than or equal to said single threshold value, in each set of successive steps updating of the second end-of-discharge voltage threshold consisting in lowering said second end-of-discharge voltage threshold by a predetermined fourth value if the parameter is lower than the threshold value,

determining the initial end-of-discharge voltage threshold by computing the mean value of the first and second end-of-discharge voltage thresholds updated if applicable.

19. The method according to claim 18, wherein the threshold value is 30 mV.

20. The method according to claim 18, wherein the predetermined third value is equal to 10 mV.

21. The method according to claim 18, wherein the predetermined fourth value is equal to 10 mV.

22. The method according to claim 12, wherein the battery is a lead battery.