Method and arrangement for determination of the state of charge of a battery

• US 6,943,528 B2
• Filed: 11/08/2001
• Issued: 09/13/2005
• Est. Priority Date: 11/17/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schoch, Eberhard
• Primary Examiner(s): Sparks, Donald
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US10/181,312
• Publication Number:
  US 20030052690A1
• Time in Patent Office: 1,405 Days
• Field of Search: 320/132, 320/130, 320/134, 320/136, 320/137, 320/149, 320/151, 320/152, 320/127, 320/128, 324/426, 324/430, 324/433, 324/425
• US Class Current: 320/132
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3835 involving only voltage measurements

Abstract

Method of determining the state of charge soc of a battery, in particular a starting battery of a motor vehicle; the state of charge being calculated, in a first operating range, on the basis of a model calculation in which a measured and a calculated battery voltage U_Batt, U_Batt, are balanced, using feedback.

Claims

1. A method of determining a state of charge of a battery, comprising:

performing a model calculation in which a measured battery voltage and a calculated battery voltage are adjusted using feedback;

in a presence of a first operating range of the battery, calculating the state of charge on the basis of the model calculation;

calculating, on the basis of the model calculation, an off-load voltage U_R from which the state of charge of the battery is derivable; and

in a presence of a second operating range of the battery, determining the state of charge on the basis of a measurement of a battery current and an off-load voltage that are one of calculated and estimated last,

wherein the state of charge of the battery is calculated according to the formula state of charge =f(U_R)=(U_R−

U_R,min)/(U_R,max−

U_R,min).

2. The method according to claim 1, wherein:

the battery includes a starting battery of a motor vehicle.

3. The method according to claim 1, wherein:

the first operating range is present if one of a battery current and a discharging current is greater than a minimum battery current.

4. A method of determining a state of charge of a battery, comprising:

performing a model calculation in which a measured battery voltage and a calculated battery voltage are adjusted using feedback; and

in a presence of a first operating range of the battery, calculating the state of charge on the basis of the model calculation;

wherein the state of charge of the battery is calculated according to the formula state of charge =f(U_R)=(U_R−

U_R,min)/(U_R,max−

U_R,min).

5. The method according to claim 4, wherein:

the battery includes a starting battery of a motor vehicle.

6. The method according to claim 4, wherein:

the first operating range is present if one of a battery current and a discharging current is greater than a minimum battery current.

7. A method of determining a state of charge of a battery, comprising:

performing a model calculation in which a measured battery voltage and a calculated battery voltage are adjusted using feedback;

in a presence of a first operating range of the battery, calculating the state of charge on the basis of the model calculation; and

in a presence of a second operating range of the battery, determining the state of charge on the basis of a measurement of a battery current and an off-load voltage that are one of calculated and estimated last.

8. The method according to claim 7, wherein:

the battery current and the off-load voltage are one of calculated and estimated last in the presence of the first operating range.

9. The method according to claim 7, wherein:

the second operating range is present when the battery current is no more than a minimum battery current.

10. The method according to claim 7, wherein:

the battery includes a starting battery of a motor vehicle.

11. The method according to claim 7, wherein:

the first operating range is present if one of a battery current and a discharging current is greater than a minimum battery current.

12. An arrangement for determining a state of charge of a battery, comprising:

a monitoring device that determines the state of charge of the battery by calculating an off-load voltage in a first operating range of the battery, on the basis of a model calculation in which a measured battery voltage and a calculated battery voltage are balanced by feedback, the monitoring device further determining the state of charge of the battery in a second operating range, on the basis of a measurement of a battery current and an off-load voltage that are one of calculated and estimated last.

13. The arrangement according to claim 12, wherein.

the battery includes a starting battery of a motor vehicle.

14. The arrangement according to claim 12, wherein:

the monitoring device includes a Kalman filter.

15. The arrangement according to claim 12, wherein:

the battery current and the off-load voltage are one of calculated and estimated last in the presence of the first operating range.