METHODS FOR MONITORING THE STATE OF A BATTERY IN A MOTOR VEHICLE

• US 20160117906A1
• Filed: 10/22/2015
• Published: 04/28/2016
• Est. Priority Date: 10/22/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: KARDEN, Eckhard, EIFERT, Mark
• Granted Patent: US 10,126,372 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G08B 21/185 Electrical failure alarms

Abstract

An internal temperature of a battery is determined at defined intervals at different moments in time and is transmitted to an evaluation unit, which continuously determines a temperature gradient at least from the temperature values by dividing the temperature change in an interval by the time change in this interval. At least one limit value for the temperature gradient is stored in the evaluation unit, and the evaluation unit generates an alarm signal when the temperature gradient determined by the evaluation unit reaches this limit value.

Claims

1. A method for monitoring a battery in a motor vehicle comprising:

determining at defined intervals at different moments in time an internal temperature of the battery;

determining by an evaluation unit a temperature gradient by dividing a change in the internal temperature by a time associated with one of the defined intervals; and

generating by the evaluation unit an alarm signal when the temperature gradient reaches a limit value.

2. The method as claimed in claim 1, wherein the battery is part of a low-voltage system of the motor vehicle.

3. The method as claimed in claim 1, wherein the internal temperature of the battery is estimated based on a measured temperature from a temperature sensor at a pole of the battery.

4. The method as claimed in claim 1 further comprising processing by the evaluation unit temperature signals prior to determining the temperature gradient.

5. The method as claimed in claim 4 further comprising calculating a mean value of the internal temperatures falling within a predefined range of values for a predefined monitoring interval while excluding the internal temperatures associated with a change between two successive internal temperatures within the monitoring interval that exceed a predefined limit value.

6. The method as claimed in claim 5 further comprising updating the mean value to include the excluded internal temperatures when a time within which the internal temperatures have been continuously dismissed reaches a predefined value.

7. The method as claimed in claim 1 further comprising correcting the internal temperatures based on an external temperature of the battery.

8. The method as claimed in claim 1 further comprising selecting the limit value according to an operating state of the motor vehicle.

9. The method as claimed in claim 1, wherein the alarm signal is generated only if the temperature gradient reaches the limit value and then remains constant or rises.

10. The method as claimed in claim 1, wherein the alarm signal is generated only if the temperature gradient reaches the limit value during a period in which a charge current for the battery is rising.

11. A method for monitoring a battery of a motor vehicle comprising:

generating by an evaluation unit an alarm signal in response to a rate of change in internal temperature of the battery achieving a limit value, selected according to a current operating state of the motor vehicle such that the limit value is lower during standstill than during a driving operation, during a period in which a charge current for the battery is rising.

12. The method as claimed in claim 11 further comprising estimating the internal temperature based on data from a temperature sensor at a pole of the battery.

13. The method as claimed in claim 11 further comprising correcting the internal temperature based on an external temperature of the battery.

14. The method as claimed in claim 11, wherein the alarm signal is generated only if the internal temperature of the battery achieves the limit value and then remains constant or rises.

15. A motor vehicle comprising:

a battery; and

an evaluation unit configured to generate an alarm signal in response to a rate of change in internal temperature of the battery achieving a limit value, selected according to a current operating state of the motor vehicle, during a period in which a charge current for the battery is rising.

16. The motor vehicle as claimed in claim 15, wherein the evaluation unit is further configured to estimate the internal temperature based on data from a temperature sensor at a pole of the battery.

17. The motor vehicle as claimed in claim 15, wherein the evaluation unit is further configured to correct the internal temperature based on an external temperature of the battery.

18. The motor vehicle as claimed in claim 15, wherein the evaluation unit is configured to generate the alarm signal only if the internal temperature of the battery achieves the limit value and then remains constant or rises.