Method and apparatus for estimating state of health (SOH) of battery

• US 20160187428A1
• Filed: 12/23/2015
• Published: 06/30/2016
• Est. Priority Date: 12/26/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Basu, Suman, Yeo, Taejun, Hariharan, Krishnan S.
• Granted Patent: US 10,459,034 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health

Abstract

A method and apparatus for estimating a state of health (SOH) of a battery are provided. The method includes measuring a voltage and a partial discharge time of the battery, acquiring a normalized partial discharge time using a battery model of a reference battery normalized with respect to a time, calculating a full discharge time of the battery based on the partial discharge time and the normalized partial discharge time, and estimating the SOH based on a ratio between a stored full discharge time of the reference battery and the full discharge time of the battery.

Claims

1. A method of estimating a state of health (SOH) of a battery, the method comprising:

measuring a voltage and a partial discharge time of the battery;

acquiring a normalized partial discharge time using a battery model normalized with respect to a time;

calculating a full discharge time of the battery based on the partial discharge time and the normalized partial discharge time; and

estimating the SOH based on a ratio between a stored full discharge time of a reference battery and the full discharge time of the battery.

2. The method of claim 1, wherein the battery model is a graph showing a change in a discharge voltage of the reference battery over time.

3. The method of claim 1, wherein the acquiring of the normalized partial discharge time comprises normalizing the battery model of the reference battery with respect to the time.

4. The method of claim 1, wherein the measuring of the voltage and the partial discharge time comprises measuring a first voltage of the battery at a first time and measuring a second voltage of the battery at a second time, and

wherein an interval between the first time and the second time corresponds to the partial discharge time.

5. The method of claim 4, wherein the acquiring of the normalized partial discharge time comprises acquiring a first normalized time corresponding to the first voltage and a second normalized time corresponding to the second voltage from the normalized battery model, and

wherein an interval between the first normalized time and the second normalized time corresponds to the normalized partial discharge time.

6. The method of claim 5, wherein the calculating of the full discharge time comprises calculating the full discharge time of the battery based on a ratio between the partial discharge time and the normalized partial discharge time.

7. The method of claim 1, further comprising predicting a loss of a cathode active material and estimating a capacity of the battery.

8. A computer program embodied on a non-transitory computer readable medium, the computer program being configured to control a processor to perform the method of claim 1 through a combination with hardware.

9. An apparatus for estimating a state of health (SOH) of a battery, the apparatus comprising:

a measurer configured to measure a voltage and a partial discharge time of the battery; and

a processor configured to acquire a normalized partial discharge time using a battery model normalized with respect to a time, to calculate a full discharge time of the battery based on the partial discharge time and the normalized partial discharge time, and to estimate the SOH based on a ratio between a stored full discharge time of a reference battery and the full discharge time of the battery.

10. The apparatus of claim 9, wherein the battery model is a graph showing a change in a discharge voltage of the reference battery over time.

11. The apparatus of claim 9, wherein the processor is configured to normalize the battery model of the reference battery with respect to the time.

12. The apparatus of claim 9, wherein the measurer is configured to measure a first voltage of the battery at a first time and measure a second voltage of the battery at a second time, and

wherein an interval between the first time and the second time corresponds to the partial discharge time.

13. The apparatus of claim 12, wherein the processor is configured to acquire a first normalized time corresponding to the first voltage and a second normalized time corresponding to the second voltage from the normalized battery model, and

wherein an interval between the first normalized time and the second normalized time corresponds to the normalized partial discharge time.

14. The apparatus of claim 13, wherein the processor is configured to calculate the full discharge time of the battery based on a ratio between the partial discharge time and the normalized partial discharge time.

15. The apparatus of claim 9, wherein the processor is configured to predict a loss of a cathode active material and to estimate a capacity of the battery.

16. A method of estimating a state of health (SOH) of a battery, the method comprising:

measuring a voltage and a partial charge time of the battery;

acquiring a normalized partial charge time using a battery model normalized with respect to a time;

calculating a full charge time of the battery based on the partial charge time and the normalized partial charge time; and

estimating the SOH based on a ratio between a stored full charge time of a reference battery and the full charge time of the battery.

17. The method of claim 16, wherein the battery model is a graph showing a change in a charging voltage of the reference battery over time.

18. The method of claim 16, wherein the measuring of the voltage and the partial charge time comprises measuring a first voltage of the battery at a first time and measuring a second voltage of the battery at a second time, and

wherein an interval between the first time and the second time corresponds to the partial charge time.

19. The method of claim 18, wherein the acquiring of the normalized partial charge time comprises acquiring a first normalized time corresponding to the first voltage and a second normalized time corresponding to the second voltage from the normalized battery model, and

wherein an interval between the first normalized time and the second normalized time corresponds to the normalized partial charge time.

20. The method of claim 19, wherein the calculating of the full charge time comprises calculating the full charge time of the battery based on a ratio between the partial charge time and the normalized partial charge time.