SYSTEM AND METHODS FOR DETECTION OF INTERNAL SHORTS IN BATTERIES

• US 20140266229A1
• Filed: 03/12/2014
• Published: 09/18/2014
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Tiax, LLC
• Original Assignee: Tiax, LLC
• Inventors: McCoy, Christopher H.
• Granted Patent: US 10,295,606 B2
• Time in Patent Office: Days
• US Class Current: 324/434
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: G01R 31/3865 related to manufacture, e.g. testing after manufacture
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for short detection in a battery pack, the battery pack including a plurality of cells, the method including: connecting a short detection module to the battery pack; determining by the short detection module that the battery pack is at rest; and selecting a first cell in the battery pack for testing for a short, wherein the testing includes: connecting a voltage source to the first cell; measuring a current of the first cell; and determining based on the measured current of the first cell whether the first cell contains a short.

Claims

1. A method for short detection in a battery pack, the battery pack comprising a plurality of cells, the method comprising:

connecting a short detection module to the battery pack;

determining by the short detection module that the battery pack is at rest; and

selecting a first cell in the battery pack for testing for a short, wherein the testing comprises;

connecting a voltage source to the first cell;

measuring a current of the first cell; and

determining based on the measured current of the first cell whether the first cell contains a short.

2. The method of claim 1, further comprising, before connecting the voltage course to the first cell:

measuring a voltage of the first cell, and storing the measured voltage; and

setting a voltage source to output the stored measured voltage.

3. The method of claim 1, further comprising varying an output voltage of the voltage source to achieve a minimum current from the first cell after connecting the voltage source to the first cell;

and

determining based on the measured current of the first cell whether the first cell contains a short after achieving the minimum current from the first cell.

4. The method of claim 1, wherein the plurality of cells in the battery pack are connected in parallel.

5. The method of claim 1, wherein the plurality of cells in the battery pack are connected in series.

6. The method of claim 1, wherein the plurality of cells in the battery pack are connected in a combination of parallel and series.

7. The method of claim 1, wherein the first cell comprises a block of cells in the battery pack.

8. The method of claim 1, wherein the plurality of cells comprises one of lithium-ion cells, lithium-air cells, and lithium-metal based cells.

9. The method of claim 1, wherein the first cell is determined to contain a short based on a measured current that increases over time, and wherein the first cell is determined to not contain a short based on a measured current that is stable over time.

10. The method of claim 9, further comprising selecting a second cell of the plurality of cells for testing.

11. The method of claim 10, wherein the battery pack is connected to the short detection module such that each of the plurality of cells is addressed separately for testing.

12. The method of claim 1, further comprising:

after connecting the voltage source to the first cell, disconnecting the voltage source from the first cell;

reconnecting the voltage source to the first cell; and

measuring the current of the first cell after reconnecting the voltage source to the first cell.

13. The method of claim 12, wherein the first cell is determined to contain a short based on a transient spike in the measured current after reconnecting the voltage source to the first cell.

14. A system for short detection in a battery pack comprising a plurality of cells, comprising:

a cell addressing matrix and control configured to be connected to the battery pack such that each of the plurality of cells is addressed separately for testing;

a voltage source and a current measurement module configured to be connected to the plurality of cells via the cell addressing matrix and control;

a control logic configured to determine whether a cell of the plurality of cells contains a short based on input from the current measurement module.

15. The system of claim 14, wherein the system further comprises:

a memory configured to store a measured voltage for each of the cells of the plurality of cells; and

a voltage measurement module configured to be connected to the plurality of cells via the cell addressing matrix and control, and is configured to perform a method comprising;

selecting a first cell in the battery pack for testing for a short by the cell addressing matrix and control, wherein the testing comprises;

connecting the voltage measurement module to the first cell by the cell addressing matrix and control measuring a voltage of the first cell by the voltage measurement module;

storing the measured voltage in the memory;

setting the voltage source to output the stored measured voltage;

connecting the voltage source and the current measurement module to the first cell by the cell addressing matrix and control;

measuring a current of the first cell by the current measurement module; and

determining based on the measured current of the first cell whether the first cell contains a short by the control logic.

16. The system of claim 14, wherein the system is configured to perform a method comprising:

selecting a first cell in the battery pack for testing for a short by the cell addressing matrix and control, wherein the testing comprises;

connecting the voltage source and the current measurement module to the first cell by the cell addressing matrix and control;

varying an output voltage of the voltage source to achieve a minimum current from the first cell after connecting the voltage source to the first cell; and

measuring a current of the first cell by the current measurement module; and

determining based on the measured current of the first cell whether the first cell contains a short by the control logic after achieving the minimum current from the first cell.

17. The system of claim 14, wherein the first cell is determined to contain a short based on a measured current that increases over time.

18. The system of claim 14, wherein the first cell is determined to not contain a short based on a measured current that is stable over time.

19. The system of claim 14, wherein the method further comprises:

after connecting the voltage source to the first cell, disconnecting the voltage source from the first cell by the cell addressing matrix and control;

reconnecting the voltage source to the first cell by the cell addressing matrix and control; and

measuring the current of the first cell by the current measurement module after reconnecting the voltage source to the first cell.

20. The system of claim 19, wherein the first cell is determined to contain a short based on a transient spike in the measured current after reconnecting the voltage source to the first cell.