Method of calculating remaining battery capacity

• US 6,507,194 B2
• Filed: 03/28/2002
• Issued: 01/14/2003
• Est. Priority Date: 03/30/2001
• Status: Expired due to Term

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Suzuki, Katsuhiro
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US10/107,494
• Publication Number:
  US 20020149373A1
• Time in Patent Office: 292 Days
• Field of Search: 324/427, 324/428, 324/426, 320/134, 320/136
• US Class Current: 324/428
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The method of calculating remaining battery capacity specifies battery discharge efficiency with discharge rate and/or temperature as parameters, and calculates remaining battery capacity from integrated discharge current based on the specified discharge efficiency. This method of calculation stores discharge efficiency as an nth order function of discharge rate and/or temperature where n is 2 or greater, computes discharge efficiency based on the stored nth order function with discharge rate and/or temperature as parameters, and calculates remaining battery capacity based on the computed discharge efficiency.

Claims

1. A method of calculating remaining battery capacity by specifying battery discharge efficiency with discharge rate as a parameter, and calculating remaining battery capacity from integrated discharge current based on the specified discharge efficiency,

wherein discharge efficiency is stored as an nth order function of discharge rate where n is 2 or greater, discharge efficiency is computed based on the stored nth order function with discharge rate as a parameter, and remaining battery capacity is calculated based on the computed discharge efficiency.

2. A method of calculating remaining battery capacity as recited in claim 1 wherein discharge efficiency is stored as an 3^rd order function of discharge rate, discharge efficiency is computed based on the stored 3^rd order function with discharge rate as a parameter, and remaining battery capacity is calculated based on the computed discharge efficiency.

3. A method of calculating remaining battery capacity as recited in claim 2 wherein discharge efficiency is stored as the 3^rd order function of discharge rate below, discharge efficiency is computed based on this 3^rd order function with discharge rate as a parameter, and remaining battery capacity is calculated based on the computed discharge efficiency,

4. A method of calculating remaining battery capacity as recited in claim 3 wherein the constants, a through d, change corresponding to each temperature.

5. A method of calculating remaining battery capacity by specifying battery discharge efficiency with temperature as a parameter, and calculating remaining battery capacity from integrated discharge current based on the specified discharge efficiency,

wherein discharge efficiency is stored as an nth order function of temperature where n is 2 or greater, discharge efficiency is computed based on the stored nth order function with temperature as a parameter, and remaining battery capacity is calculated based on the computed discharge efficiency.

6. A method of calculating remaining battery capacity as recited in claim 5 wherein discharge efficiency is stored as an 3^rd order function of temperature, discharge efficiency is computed based on the stored 3^rd order function with temperature as a parameter, and remaining battery capacity is calculated based on the computed discharge efficiency.

7. A method of calculating remaining battery capacity as recited in claim 6 wherein discharge efficiency is stored as the 3^rd order function of temperature below, discharge efficiency is computed based on this 3^rd order function with temperature as a parameter, and remaining battery capacity is calculated based on the computed discharge efficiency,

8. A method of calculating remaining battery capacity by specifying battery discharge efficiency with temperature and discharge rate as parameters, and calculating remaining battery capacity from integrated discharge current based on the specified discharge efficiency,

wherein discharge efficiency is stored as an nth order function of temperature and discharge rate where n is 2 or greater, discharge efficiency is computed based on the stored nth order function with temperature and discharge rate as parameters, and remaining battery capacity is calculated based on the computed discharge efficiency.

9. A method of calculating remaining battery capacity as recited in claim 8 wherein discharge efficiency is computed from a 3^rd order function with temperature and discharge rate as parameters, and remaining battery capacity is calculated based on the computed discharge efficiency.

10. A method of calculating remaining battery capacity as recited in claim 9 wherein discharge efficiency is stored as the 3^rd order function of discharge rate and temperature below, discharge efficiency is computed based on this 3^rd order function with discharge rate and temperature as parameters, and remaining battery capacity is calculated based on the computed discharge efficiency,

11. A method of calculating remaining battery capacity by specifying minimum battery voltage with discharge rate as a parameter, and determining remaining battery capacity by detecting when the voltage of the discharging batteries becomes equal to the specified minimum voltage,

wherein minimum voltage is stored as an nth order function of discharge rate where n is 2 or greater, minimum voltage is computed based on the stored nth order function with discharge rate as a parameter, and remaining battery capacity is assumed to be a prescribed capacity when battery voltage drops to the computed minimum voltage.

12. A method of calculating remaining battery capacity as recited in claim 11 wherein minimum voltage is specified as an 3^rd order function with discharge rate as a parameter.

13. A method of calculating remaining battery capacity as recited in claim 12 wherein minimum voltage is stored as the 3^rd order function of discharge rate below,

14. A method of calculating remaining battery capacity as recited in claim 13 wherein the constants, A through D, change corresponding to each temperature.

15. A method of calculating remaining battery capacity as recited in claim 11 wherein the minimum voltage is set to the voltage at a remaining battery capacity of 0 to 10%.

16. A method of calculating remaining battery capacity by specifying minimum battery voltage with temperature as a parameter, and determining remaining battery capacity by detecting when the voltage of the discharging batteries becomes equal to the specified minimum voltage,

characterized in that minimum voltage is stored as an nth order function of temperature where n is 2 or greater, minimum voltage is computed based on the stored nth order function with temperature as a parameter, and remaining battery capacity is assumed to be a prescribed capacity when battery voltage drops to the computed minimum voltage.

17. A method of calculating remaining battery capacity as recited in claim 16 wherein minimum voltage is specified as an 3^rd order function with temperature as a parameter.

18. A method of calculating remaining battery capacity as recited in claim 17 wherein minimum voltage is stored as the 3^rd order function of temperature below,

19. A method of calculating remaining battery capacity as recited in claim 16 wherein the minimum voltage is set to the voltage at a remaining battery capacity of 0 to 10%.

20. A method of calculating remaining battery capacity by specifying minimum battery voltage with temperature and discharge rate as parameters, and determining remaining battery capacity by detecting when the voltage of the discharging batteries becomes equal to the specified minimum voltage,

characterized in that minimum voltage is stored as an nth order function of temperature and discharge rate where n is 2 or greater, minimum voltage is computed based on the stored nth order function with temperature and discharge rate as parameters, and remaining battery capacity is assumed to be a prescribed capacity when battery voltage drops to the computed minimum voltage.

21. A method of calculating remaining battery capacity as recited in claim 20 wherein minimum voltage is specified as an 3^rd order function with temperature and discharge rate as parameters.

22. A method of calculating remaining battery capacity as recited in claim 21 wherein minimum voltage is stored as the 3^rd order function of temperature and discharge rate below,

23. A method of calculating remaining battery capacity as recited in claim 20 wherein the minimum voltage is set to the voltage at a remaining battery capacity of 0 to 10%.