Temperature abnormality detecting apparatus and method for secondary battery

• US 20040257089A1
• Filed: 06/10/2004
• Published: 12/23/2004
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Aridome, Koji
• Granted Patent: US 7,492,129 B2
• Time in Patent Office: Days
• US Class Current: 324/430
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/633 characterised by algorithms, flow charts, software details or the like
• CPC Class Codes: H01M 10/6563 with forced flow, e.g. by blowers
• CPC Class Codes: H01M 10/663 the system being an air-conditioner or an engine
• CPC Class Codes: H01M 50/569 Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals battery terminal connectors with integrated measuring arrangements G01R31/364
• CPC Class Codes: H01M 6/42 Grouping of primary cells into batteries H01M6/40 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery ECU includes i) a circuit connected to a plurality of battery temperature sensors provided on a plurality of battery cells which make up a battery, and a cooling fan, the circuit detecting operation of the cooling fan, and ii) a circuit that determines that there is a temperature abnormality in a battery based on the difference between a maximum value and a minimum value of battery temperatures measured by the battery temperature sensors only when the period of time during which temperature increases within a predetermined period of time in the battery temperatures measured by the battery temperature sensors continue to be less than a threshold value is longer than a predetermined period of time, and the cooling fan has been operating for a longer period of time than a suitable cooling fan operating time obtained based on the difference between the maximum value and the minimum value of the measured battery temperatures.

Claims

1. A temperature abnormality detecting apparatus that detects a temperature abnormality in a secondary battery having a plurality of battery cells, comprising:

a measuring device that measures temperatures of at least two battery cells from among the plurality of battery cells;

a temperature equalizing device that equalizes the temperatures of the plurality of battery cells; and

a first detector that detects a temperature abnormality in the secondary battery based on the temperatures of the battery cells measured by the measuring device, corresponding to operation of the temperature equalizing device.

2. The temperature abnormality detecting apparatus according to claim 1, wherein the temperature equalizing device equalizes the temperatures of the plurality of battery cells by cooling the plurality of battery cells by supplying a cooling medium thereto, the temperature abnormality detecting apparatus further comprising:

a determining device that determines whether the secondary battery has been sufficiently cooled by the cooling medium, wherein the first detector detects whether there is a temperature abnormality in the secondary battery when it is determined by the determining device that the secondary battery has been sufficiently cooled.

3. The temperature abnormality detecting apparatus according to claim 2, wherein the determining device includes a calculating device which calculates a cooling time to sufficiently cool the secondary battery based on a temperature difference between the temperatures of the battery cells measured by the measuring devices, and a pre-stored relationship between the temperature difference and the cooling time, and a second detector that detects an operating time of the temperature equalizing device, and

wherein the determining device determines whether the secondary battery has been sufficiently cooled based on the calculated cooling time and the detected operating time.

4. The temperature abnormality detecting apparatus according to claim 1, further comprising:

a first controller which detects a temperature increase in a predetermined period of time in the measured temperature of each of the battery cells, and which controls the detection by the first detector to be executed when the temperature increase in at least one of the battery cells is equal to, or less than, a predetermined amount of change.

5. The temperature abnormality detecting apparatus according to claim 1, further comprising:

a second controller which detects a temperature increase in a predetermined period of time in the measured temperature of each of the battery cells, and which controls the detection by the first detector to be executed when the temperature increases in all of the battery cells are equal to, or less than, a predetermined amount of change.

6. The temperature abnormality detecting apparatus according to claim 1, wherein the first detector detects a temperature abnormality in the secondary battery when a difference between the measured temperature of each of the battery cells is greater than a predetermined value.

7. A temperature abnormality detecting method for detecting a temperature abnormality in a secondary battery having a plurality of battery cells, comprising the steps of:

a) measuring temperatures of at least two battery cells from among the plurality of battery cells;

b) equalizing the temperatures of the plurality of battery cells; and

c) detecting a temperature abnormality in the secondary battery based on the measured temperatures of the battery cells, corresponding to the execution of step a).

8. The temperature abnormality detecting method according to claim 7, wherein the temperatures of the plurality of battery cells are equalized by cooling the plurality of battery cells by supplying a cooling medium thereto in step b) that the temperature abnormality detecting method further comprising the step of:

determining whether the secondary battery has been sufficiently cooled by the cooling medium, wherein step c) is executed when it is determined that the secondary battery has been sufficiently cooled by the cooling medium in step d).

9. The temperature abnormality detecting method according to claim 8, wherein step d) includes calculating a cooling time to sufficiently cool the secondary battery based on a temperature difference between the temperatures of the battery cells measured in step a), and a pre-stored relationship between the temperature difference and the cooling time, detecting an execution period of step b), and

wherein whether the secondary battery has been sufficiently cooled is determined based on the calculated cooling time and the detected execution period.

10. The temperature abnormality detecting method according to claim 7, further comprising the step of:

e) detecting a temperature increase in a predetermined period of time in the temperature of each of the battery cells measured in step a), and controlling step c) to be executed when the measured temperature increase in at least one of the battery cells is equal to, or less than, a predetermined amount of change.

11. The temperature abnormality detecting method according to claim 7, further comprising the step of:

f) detecting a temperature increase in a predetermined period of time in the measured temperature of each of the battery cells measured in step a), and controlling step c) to be executed when the temperature increases in all of the battery cells are equal to, or less than, a predetermined amount of change.

12. The temperature abnormality detecting method according to claim 7, wherein step c) detects a temperature abnormality in the secondary battery when a difference in the temperatures of the battery cells measured in step a) is greater than a predetermined value.

13. A temperature abnormality detecting apparatus that detects a temperature abnormality in a secondary battery having a plurality of battery cells, comprising:

measuring means for measuring temperatures of at least two battery cells from among the plurality of battery cells;

temperature equalizing means for equalizing the temperatures of the plurality of the battery cells; and

detecting means for detecting a temperature abnormality in the secondary battery based on the temperatures of the battery cells measured by the measuring means, corresponding to operation of the temperature equalizing means.