Method and apparatus of estimating state of health of battery

• US 20070001679A1
• Filed: 06/30/2006
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Cho, Il, Kim, Do, Jung, Do
• Granted Patent: US 7,615,967 B2
• Time in Patent Office: Days
• US Class Current: 324/426
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed is a method and apparatus of estimating a state of health (SOH) of a battery using internal resistance, which has been found to act as a parameter exerting the greatest influence on the SOH of the battery. The method comprises the steps of: storing an SOH estimation table constructing SOH values corresponding to various values of internal resistance according to temperature and a state of charge (SOC) in a memory; performing measurement of the temperature and estimation of the SOC of the battery when a request is made to estimate the SOH; detecting the internal resistance value of the battery; and reading the SOH values corresponding to the measured temperature, the estimated SOC of the battery, and the detected internal resistance value of the battery from the SOH estimation table.

Claims

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

storing SOH values corresponding to various values of internal resistance in a memory;

detecting the internal resistance value of the battery when a request is made to estimate the SOH; and

reading the SOH value corresponding to the detected internal resistance value from the memory.

2. The method according to claim 1, wherein the internal resistance value is calculated through voltage and current, which are measured for a predetermined time during actual operation of the battery.

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

storing an SOH estimation table constructing SOH values corresponding to various values of internal resistance according to temperature and a state of charge (SOC) in a memory;

performing measurement of the temperature and estimation of the SOC of the battery when a request is made to estimate the SOH;

detecting the internal resistance value of the battery; and

reading the SOH values corresponding to the measured temperature, the estimated SOC of the battery, and the detected internal resistance value of the battery from the SOH estimation table.

4. The method according to claim 3, wherein the internal resistance value is calculated through voltage and current, which are measured for a predetermined time during actual operation of the battery.

5. The method according to claim 3, wherein the SOH estimation table is constructed with values within actual operation temperature and SOC ranges of the battery.

6. An apparatus of estimating a state of health (SOH) of a battery, comprising:

a memory storing SOH values corresponding to various values of internal resistance;

a current and voltage meter measuring current and voltage of the battery; and

a controller performing measurement of the current and voltage of the battery through the current and voltage meter and calculation of the internal resistance value from the measured current and voltage when a request is made to estimate the SOH, and reading the SOH value corresponding to the calculated internal resistance value from the memory.

7. An apparatus of estimating a state of health (SOH) of a battery, comprising:

a memory storing an SOH estimation table constructing SOH values corresponding to various values of internal resistance according to temperature and a state of charge (SOC);

a current and voltage meter measuring current and voltage of the battery;

a temperature meter measuring the temperature;

an SOC estimator estimating the SOC of the battery; and

a controller performing measurement of the temperature through the temperature meter and estimation of the SOC of the battery through the SOC estimator when a request is made to estimate the SOH, measuring the current and voltage of the battery through the current and voltage meter, calculating the internal resistance value from the measured current and voltage, and reading the SOH values corresponding to the measured temperature, the estimated SOC of the battery, and the calculated internal resistance value of the battery from the SOH estimation table.

8. The apparatus according to claim 7, wherein the SOH estimation table is constructed with values within actual operation temperature and SOC ranges of the battery.