Method for diagnosing the state of health of a battery

• US 8,589,097 B2
• Filed: 01/26/2011
• Issued: 11/19/2013
• Est. Priority Date: 01/27/2010
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Kirchev, Angel Zhivkov
• Primary Examiner(s): Kundu, Sujoy
• Assistant Examiner(s): Desta, Elias
• Application Number:
  US13/522,148
• Publication Number:
  US 20120296586A1
• Time in Patent Office: 1,028 Days
• Field of Search: 702/58, 702/63, 702/64, 702/79, 702/108, 700/297, 340/636.1, 340/636.21, 324/145, 324/426, 320/127
• 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:

partially discharging the battery at a constant current,

measuring the battery voltage during partial discharging,

determining a first state-of-charge value from the battery voltage during partial discharging,

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

calculating, with a processor, 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, further comprising

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

measuring the open circuit voltage of the battery.