Power source health assessment methods and systems thereof

• US 8,283,891 B2
• Filed: 03/21/2008
• Issued: 10/09/2012
• Est. Priority Date: 03/21/2008
• Status: Active Grant

• Current Assignee: Rochester Institute of Technology
• Original Assignee: Rochester Institute of Technology
• Inventors: Anbari, Omar
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US12/077,896
• Publication Number:
  US 20090237087A1
• Time in Patent Office: 1,663 Days
• Field of Search: 324/426, 324/429, 324/433, 320/103, 320/134, 320/135, 320/136, 320/132, 320/137, 320/138, 320/148, 320/149, 320/161, 320/162
• US Class Current: 320/132
• CPC Class Codes: G01R 31/379 for lead-acid batteries
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health

Abstract

A method and system for assessing health of a power source includes measuring voltage and current of a power source in a system using a device in the system as the load. An internal resistance of the power source is determined based on the measured voltage and current. A health assessment of the power source is determined and provided based at least on the determined internal resistance and a stored baseline internal resistance for the power source.

Claims

1. A method for assessing health of a power source, the method comprising:

measuring voltage and current of a power source in a system at a start and a stop of a transient period of time using a device in the system as the load;

determining an internal resistance of the power source based on a difference of the measured voltages at the start and stop of the transient period of time divided by a difference of the measured current at the start and stop of the transient period of time; and

determining and providing a health assessment of the power source based on at least on the determined internal resistance and a stored baseline internal resistance for the power source.

2. The method as set forth in claim 1 further comprising triggering the measuring based on at least one event in the system.

3. The method as set forth in claim 2 wherein at least one event is a start of the system.

4. The method as set forth in claim 1 wherein the measuring voltage and current of the power source further comprises measuring the voltage and current at a sampling rate above at least a first frequency.

5. The method as set forth in claim 4 wherein the first frequency is at least two kHz.

6. The method as set forth in claim 1 wherein the determining and providing the health assessment of the power source further comprises:

comparing the determined internal resistance against the stored baseline internal resistance for the power source; and

providing a failing health assessment of the power source if the comparison indicates the determined internal resistance is more than a first percentage above the stored baseline internal resistance.

7. The method as set forth in claim 6 wherein the first percentage is about twenty-five percent or greater.

8. The method as set forth in claim 1 further comprising applying a transient to the power source for a first period of time, wherein the measuring the voltage and current of the power source occurs at least partially during the application of the transient.

9. The method as set forth in claim 8 wherein the first period of time is 400 milliseconds or less.

10. The method as set forth in claim 8 wherein the device used as the load and which applies the transient comprises a starter system.

11. The method as set forth in claim 1 further comprising:

measuring an ambient temperature of the power source; and

comparing the measured temperature against stored temperature efficiency data for the power source;

wherein the determining and providing a health assessment of the power source further comprises determining and providing the health assessment of the power source based on the comparison of the measured temperature against stored temperature efficiency data.

12. The method as set forth in claim 1 further comprising determining and providing a future prediction on when the power source will fail based on at least the determined internal resistance and stored, internal resistance life-cycle data for the power source.

13. The method as set forth in claim 1 wherein the determining further comprises determining and providing a health assessment of the device used as the load based at least on the determined internal resistance and a stored baseline internal resistance for the device used as the load the changes in the device intrinsic resistance.

14. A system for assessing health of a power source comprising:

a data acquisition system that measures voltage and current of a power source in a system at a start and a stop of a transient period of time using a device in the system as the load;

an analysis system that determines an internal resistance of the power source based on a difference of the measured voltages at the start and stop of the transient period of time divided by a difference of the measured current at the start and stop of the transient period of time; and

an assessment processing system that determines and provides a health assessment of the power source based at least on the determined internal resistance and a stored baseline internal resistance for the power source.

15. The system as set forth in claim 14 further comprising a monitoring system that triggers the data acquisition system to measure the voltage and current of the power source based on at least one event in the system.

16. The system as set forth in claim 15 wherein on at least one event is a start of the system.

17. The system as set forth in claim 14 wherein the data acquisition system measures the voltage and current at a sampling rate above at least a first frequency.

18. The system as set forth in claim 17 wherein the first frequency is at least two kHz.

19. The system as set forth in claim 14 wherein the assessment processing system compares the determined internal resistance against the stored baseline internal resistance for the power source and provides a failing health assessment of the power source if the comparison indicates the determined internal resistance is more than a first percentage above the stored baseline internal resistance.

20. The system as set forth in claim 19 wherein the first percentage is about twenty-five percent or greater.

21. The system as set forth in claim 14 further comprising a transient source system which applies a transient to the power source for a first period of time, wherein the data acquisition system measures the voltage and current of the power source occurs at least partially during the application of the transient.

22. The system as set forth in claim 21 wherein the first period of time is 400 milliseconds or less.

23. The system as set forth in claim 21 wherein the device used as the load and the transient source system comprises a starter system.

24. The system as set forth in claim 14 further comprising a temperature monitoring system that measures an ambient temperature of the power source, wherein the assessment processing system compares the measured temperature against stored temperature efficiency data for the power source and further determines and provides the health assessment of the power source based on the comparison of the measured temperature against stored temperature efficiency data.

25. The system as set forth in claim 14 wherein the assessment processing system determines and provides a future prediction on when the power source will fail based on at least the determined internal resistance and stored, internal resistance life-cycle data for the power source.

26. The system as set forth in claim 14 wherein the assessment processing system determines and provides a health assessment of the device used as the load based at least on the determined internal resistance and a stored baseline internal resistance for the device used as the load.