Industrial truck with a battery and method for operating an industrial truck with a battery

• US 20070279065A1
• Filed: 04/13/2007
• Published: 12/06/2007
• Est. Priority Date: 04/13/2006
• Status: Active Grant

• Current Assignee: Linde Material Handling GmbH (Superlift Holding SARL)
• Original Assignee: Linde Material Handling GmbH (Superlift Holding SARL)
• Inventors: Gutlein, Ralf
• Granted Patent: US 7,872,449 B2
• Time in Patent Office: Days
• US Class Current: 324/430
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables

Abstract

The invention relates to an industrial truck with at least one drive battery and at least one apparatus (A) for determining the state of charge of the battery and to a method for operating such an industrial truck. The apparatus (A) for determining the state of charge of the battery includes a device (B) for determining the dynamic internal resistance and a device (C) for determining the internal cell voltage of the battery with the aid of the dynamic internal resistance.

Claims

1. An industrial truck, comprising:

at least one drive battery; and

at least one apparatus for determining a state of charge of the battery, wherein the apparatus for determining the state of charge of the battery comprises means for determining a dynamic internal resistance and means for determining an internal cell voltage of the battery with the aid of the dynamic internal resistance.

2. The industrial truck according to claim 1, wherein the means for determining the internal cell voltage and the means for determining the dynamic internal resistance comprise at least one apparatus for determining a terminal voltage of the battery and at least one apparatus for determining a current drawn from the battery.

3. The industrial truck according to claim 1, wherein the means for determining the dynamic internal resistance comprise at least one apparatus for determining a time profile of a change in the terminal voltage of the battery and/or in the current drawn from the battery.

4. The industrial truck according to claim 2, wherein the means for determining the dynamic internal resistance comprise at least one apparatus for determining a time profile of a change in the terminal voltage of the battery and/or in the current drawn from the battery.

5. The industrial truck according to claim 1, wherein the apparatus for determining the state of charge of the battery comprises means for compensating for a diffusion overvoltage.

6. The industrial truck according to claim 2, wherein the apparatus for determining the state of charge of the battery comprises means for compensating for a diffusion overvoltage.

7. The industrial truck according to claim 3, wherein the apparatus for determining the state of charge of the battery comprises means for compensating for a diffusion overvoltage.

8. The industrial truck according to claim 1, further comprising means for detecting a threat of a deep discharge from the time profile of the internal open-circuit cell voltage are provided.

9. The industrial truck according to claim 2, further comprising means for detecting a threat of a deep discharge from the time profile of the internal open-circuit cell voltage are provided.

10. The industrial truck according to claim 3, further comprising means for detecting a threat of a deep discharge from the time profile of the internal open-circuit cell voltage are provided.

11. The industrial truck according to claim 4, further comprising means for detecting a threat of a deep discharge from the time profile of the internal open-circuit cell voltage are provided.

12. A method for operating an industrial truck, comprising:

determining an internal cell voltage of a battery with the aid of a dynamic internal resistance of the battery, and

determining a state of charge of the battery from the internal cell voltage of the battery.

13. The method for operating an industrial truck according to claim 12, wherein the dynamic battery internal resistance is determined from a time profile of a terminal voltage of the battery and of current drawn from the battery.

14. The method for operating an industrial truck according to claim 12, wherein the dynamic internal resistance is determined from a quotient of a time derivative of a terminal voltage of the battery and of a current drawn from the battery.

15. The method for operating an industrial truck according to claim 13, wherein the dynamic internal resistance is determined from a quotient of a time derivative of a terminal voltage of the battery and of a current drawn from the battery.

16. A method for operating an industrial truck according to claim 12, wherein the internal cell voltage is determined on the basis of multiplication of a current drawn from the battery and a dynamic internal resistance.

17. A method for operating an industrial truck according to claim 13, wherein the internal cell voltage is determined on the basis of multiplication of a current drawn from the battery and a dynamic internal resistance.

18. A method for operating an industrial truck according to claim 14, wherein the internal cell voltage is determined on the basis of multiplication of a current drawn from the battery and a dynamic internal resistance.

19. The method for operating an industrial truck according to claim 12, wherein an internal open-circuit cell voltage is calculated from addition of an internal cell terminal voltage and a diffusion overvoltage.

20. The method for operating an industrial truck according to claim 12, wherein the state of charge is determined from an internal open-circuit cell voltage.