Method for determining the temperature of a battery

• US 9,819,061 B2
• Filed: 04/13/2015
• Issued: 11/14/2017
• Est. Priority Date: 05/12/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Reitzle, Alexander, Hore, Sarmimala
• Primary Examiner(s): Jagan, Mirellys
• Application Number:
  US15/309,688
• Publication Number:
  US 20170133729A1
• Time in Patent Office: 946 Days
• Field of Search: 374152, 374163, 374141
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The invention relates to a method for determining the temperature of a battery, comprising the following steps: a) determining the state of charge of at least one battery cell; b) determining a change in the open-circuit voltage (V_L1, V_L2) of the at least one battery cell immediately after the end of the flow of an electric current (I_L, I_E) through the at least one battery cell; and c) determining the temperature of the at least one battery cell on the basis of the state of charge and the change in the open-circuit voltage (V_L1, V_L2). The method described above economically enables especially reliable operation of the battery that is stable over the long term.

Claims

1. A method for determining the temperature of a battery, comprising the following steps:

a) determining the state of charge of at least one battery cell;

b) determining a change in an open-circuit voltage (V_L1 or V_L2) of the at least one battery cell immediately after the end of the flow of a respective electric current (I_E, I_L) through the at least one battery cell; and

c) determining the temperature of the at least one battery cell on the basis of the state of charge and the change in the open-circuit voltage (V_L1 or V_L2).

2. The method according to claim 1, wherein the determined temperature is verified by the use of a temperature sensor.

3. The method according to claim 1, wherein the change in the open-circuit voltage (V_L1, V_L2) is determined cyclically.

4. The method according to claim 1, wherein the change in the open-circuit voltage (V_L1, V_L2) is determined during a recuperation phase of the battery.

5. The method according to claim 1, wherein the battery is a lithium-ion battery.

6. The method according to claim 1, wherein step c) of the method is carried out using a temporal change in the open-circuit voltage (V_L1, V_L2).

7. The method according to claim 6, wherein step c) of the method is carried out using an entire profile of the change in the open-circuit voltage (V_L1, V_L2).

8. The method according to claim 1, wherein the method is carried out by means of a battery control system.

9. The method according to claim 8, wherein step c) of the method is carried out on the basis of a data set that is stored the battery control system.

10. A battery system comprising a battery having at least one battery cell, the system comprising:

a means for determining the state of charge of the battery cell,

a means for determining a change in an open-circuit voltage (V_L1 or V_L2) of the at least one battery cell immediately after the end of the flow of a respective electric current (I_E, I_L) through the at least one battery cell, and

a means for determining the temperature of the at least one battery cell on the basis of the state of charge and the change in the open-circuit voltage (V_L1 or V_L2).