Battery monitoring system

• US 20080048662A1
• Filed: 08/22/2007
• Published: 02/28/2008
• Est. Priority Date: 08/22/2006
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Hirsch, Krystian, Baur, Peter, Heise, Volker
• Granted Patent: US 7,759,901 B2
• Time in Patent Office: Days
• US Class Current: 324/430
• 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

Abstract

A system for the monitoring of the state of a battery used in a vehicle and to which electrical elements comprising at least one electrical consumer and/or at least one electrical generator are connected comprises means for the detection of the battery voltage, means for the extraction of voltage frequency components from the detected battery voltage at different frequencies, means for the detection of the current flowing out of or into the battery, means for the extraction of current frequency components from the detected battery current at the same frequencies at which the voltage frequency components were extracted, means for the determination of internal impedances of the battery from the voltage frequency components and current frequency components extracted at a respective frequency, means for the storage of predetermined relationships between the internal impedance and the battery state for each of the respective frequencies and means for the determination of the battery state from the determined internal impedances and the predetermined relationships. In this connection, means are provided for the monitoring of the state of at least some of the electrical elements as well as means in order to select the time for a respective voltage and current detection in dependence on the detected state of the electrical elements and/or to fix the conditions for a respective voltage and current detection.

Claims

1. A system (10) for the monitoring of the state of a battery (12) used in a vehicle and to which electrical elements (14-18) comprising at least one electrical consumer and/or at least one electrical generator are connected, having means (20) for the detection of the battery voltage (V), means (24) for the extraction of voltage frequency components from the detected battery voltage (V) at different frequencies, means (20) for the detection of the current (I) flowing out of or into the battery (12), means for the extraction of current frequency components from the detected battery current (I) at the same frequencies at which the voltage frequency components were extracted, means (24) for the determination of internal impedances of the battery (12) from the voltage frequency components and current frequency components extracted at a respective frequency, means (24) for the storage of predetermined relationships between the internal impedance and the battery state for each of the respective frequencies and means (24) for the determination of the battery state from the determined internal impedances and the predetermined relationships,

characterized in that

means (24) are provided for the monitoring of the state of at least some of the electrical elements (14-18) as well as means (24) in order to select the time for a respective voltage and current detection in dependence on the detected state of the electrical elements (14-18) and/or to fix the conditions for a respective voltage and current detection in dependence on the detected state of the electrical elements (14-18).

2. A system in accordance with claim 1, characterized in that the electrical elements (14-18) connected to the battery (12) are monitored as to whether they effect a pulse generating a desired frequency spectrum in the battery voltage (V) or in the battery current (I);

and in that the battery voltage (V) and the battery current (I) are detected on the occurrence of a corresponding pulse.

3. A system in accordance with claim 1 or claim 2, characterized in that means (24) are provided in order to generate a load pulse in dependence on the detected state of the electrical elements (14-17) which brings about a desired frequency spectrum in the battery voltage (V) or in the battery current (I);

and in that the battery voltage (V) and the battery current (I) are detected on the generation of a corresponding load pulse.

4. A system in accordance with claim 2 or claim 3, characterized in that the sampling rate on the detection of the battery voltage (V) and of the battery current (I) is selected in dependence on the properties of the occurring pulse or of the generated load pulse.

5. A system in accordance with any one of the preceding claims, characterized in that a normalization of the detected battery voltage (V) or of the detected battery current (I) takes place in dependence on the respective battery state.

6. A system in accordance with any one of the preceding claims, characterized in that at least one of the following states is monitored as the battery state:

aging state (SoH), charge state (SoC), degree of function satisfaction (SoF).

7. A system in accordance with any one of the preceding claims, characterized in that at least the age state (SoH) is monitored as the battery state.

8. A system in accordance with any one of the preceding claims, characterized in that the battery voltage (V) and the battery current (I) are detected on the occurrence of a pulse generated by a starter/generator (14).

9. A system in accordance with claim 8, characterized in that only the pulse generated by the starter/generator (14) is used as the trigger pulse for the detection of the battery voltage (V) and of the battery current (I).

10. A system in accordance with claim 8, characterized in that the battery voltage (V) and the battery current (I) are detected on the occurrence of a pulse generated by a starter/generator (14), assisted by an additional excitation generated by a specific artificial controllable load (26).

11. A system in accordance with claim 8, characterized in that the battery voltage (V) and the battery current (I) are detected on the occurrence of a pulse generated by a starter/generator (14), supported by at least one additional artificial pulse generated via at least one electrical element, preferably an electrical consumer (16, 18), already present.

12. A system in accordance with claim 11, characterized in that the artificial pulse is generated via at least one electrical lamp and/or at least one electrical heating element.