Device and method for battery state determination

• US 20080071484A1
• Filed: 09/17/2007
• Published: 03/20/2008
• Est. Priority Date: 09/18/2006
• Status: Active Grant

• Current Assignee: Clarios Germany GmbH & Co. KG (Michael Tojner, PhD, LLD)
• Original Assignee: VB Autobatterie GmbH & Co. KGaA (Robert Bosch GmbH)
• Inventors: Meissner, Eberhard, Koch, Ingo
• Granted Patent: US 7,561,978 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm

Abstract

A method for battery state determination includes statistically assessing at least one determined characteristic variable for the battery state by means of a statistical process check.

Claims

1. A method for battery state determination comprising the steps of:

statistically assessing at least one determined characteristic variable for the battery state by performing a statistical process check.

2. The method according to claim 1, further comprising the step of identifying an implausible value for a determined characteristic variable if the absolute value of a mean scatter for the characteristic variable is greater than a defined scatter limit value.

3. The method according to claim 1, wherein the step of statistically assessing at least one determined characteristic variable for the battery state comprises defining an observation window for the at least one characteristic variable within which the at least one characteristic variable is assumed to be steady-state.

4. The method according to claim 3, wherein the step of statistically assessing at least one determined characteristic variable for the battery state further comprises identifying an implausible value, which is not caused by the battery, for a determined characteristic variable if the scatter of the characteristic variables exceeds a defined scatter limit.

5. The method according to claim 3, wherein the observation window is a time window.

6. The method according to, claim 5, wherein the observation window is chosen as a function of the dynamics of the characteristic variable.

7. The method according to claim 3, wherein the observation window is a number of successive values considered for the characteristic variable.

8. The method according to claim 3, wherein only values of the at least one characteristic variable which are within the observation window are considered in the statistical assessment.

9. The method according to claim 1, wherein the characteristic variable is the loss of capacity of a rechargeable battery.

10. The method according to claim 2, further comprising calculating at least one of the mean scatter and a mean value for the characteristic variable by filtering.

11. The method according to claim 1, wherein the step of statistically assessing at least one determined characteristic variable for the battery state is carried out with the aid of at least one type of quality control chart.

12. The method according to claim 1, further comprising determining and statistically assessing a plurality of characteristic variables at the same time.

13. The method according to claim 12, further comprising combining the plurality of-characteristic variables with one another to derive a battery state.

14. A device for battery state identification comprising:

a unit for measuring at least one of battery terminal voltage and battery terminal current;

a unit for determining at least one characteristic variable for the battery state from at least one of the measured battery terminal voltage and the measured battery current; and

an assessment unit configured to statistically assess the at least one determined characteristic variable using a statistical process check.

15. The device according to claim 14, wherein the assessment unit is further configured to identify an implausible value for a determined characteristic variable if the absolute value of a mean scatter for the characteristic variable is greater than a defined scatter limit value.

16. The device according to claim 14, wherein the assessment unit is configured to define an observation window for the at least one characteristic variable within which the at least one characteristic variable is assumed to be steady-state.

17. The device according to claim 14, wherein the assessment unit is configured to identify an implausible value, which is not caused by the battery, for a determined characteristic variable if the scatter of the characteristic variables exceeds a defined scatter limit.

18. The device according to claim 16, wherein the assessment unit defines the observation window as a time window chosen as a function of the dynamics of the characteristic variable.

19. The device according to claim 14, wherein the assessment unit is configured to assess the loss of capacity of a rechargeable battery as the characteristic variable.

20. The device according to claim 14, wherein the assessment unit utilizes a quality control charge to assess the determined characteristic variable for the battery state.