METHOD FOR DIAGNOSING THE STATE OF HEALTH OF A BATTERY

• US 20120296586A1
• Filed: 01/26/2011
• Published: 11/22/2012
• Est. Priority Date: 01/27/2010
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Kirchev, Angel Zhivkov
• Granted Patent: US 8,589,097 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/379 for lead-acid batteries
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health

Abstract

A method for diagnosing the state of health of a battery includes, determining a first state-of-charge value from the battery voltage during partial discharge at constant current, determining a second state-of-charge value from the open circuit voltage of the battery, and calculating the state of health from the difference between the first and second state-of-charge values.

Claims

1. A method for diagnosing the state of health of a battery, comprising the following steps:

determining a first state-of-charge value from the battery voltage during partial discharge at a constant current,

determining a second state-of-charge value from the open circuit voltage of the battery, and

deducing the state of health from the difference between the first and second state-of-charge values.

2. The method according to claim 1, wherein the state of health SOH is calculated from the relationship

3. The method according to claim 1, wherein the partial discharge current is comprised between C_N/10 h and C_N/1 h, C_N being the nominal capacity of the battery.

4. The method according to claim 3, wherein the partial discharge current is comprised between C_N/5 h and C_N/3 h.

5. The method according to claim 1, wherein partial discharge takes place during a time period such that the decrease of the charge of the battery is comprised between 0.5% and 2%.

6. The method according to claim 1, wherein partial discharge takes place during a time period comprised between 20 seconds and 10 minutes.

7. The method according to claim 6, wherein the partial discharge time period is comprised between 1 minute and 3 minutes.

8. The method according to claim 1, wherein the step of determining the second state-of-charge value comprises the following steps:

disconnecting the battery during a time period comprised between 60 and 300 seconds, and

measuring the open circuit voltage of the battery.