Device for reactivating an electric battery

• US 6,340,879 B1
• Filed: 02/03/2000
• Issued: 01/22/2002
• Est. Priority Date: 02/03/1999
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Bläcker, Bernhard
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/497,186
• Time in Patent Office: 719 Days
• Field of Search: 320/130, 320/131, 320/157, 320/153, 219/201, 219/209
• US Class Current: 320/153
• 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 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/623 Portable devices, e.g. mobile telephones, cameras or pacemakers
• CPC Class Codes: H01M 10/633 characterised by algorithms, flow charts, software details or the like
• CPC Class Codes: H01M 10/637 characterised by the use of reversible temperature-sensitive devices, e.g. NTC, PTC or bimetal devices; characterised by control of the internal current flowing through the cells, e.g. by switching means for preventing undesired use or discharge H01M50/572
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The invention concerns a device for reactivating an electric battery (B) which is no longer able to supply the required minimum amount of electrical power to a connected consumer unit because it was supercooled by frost. The object of the invention is to create a solution, at a justifiable cost of time and energy, which enables the consumer unit to operate as soon as possible or keep it operating after the effect of extremely low temperatures on the battery. According to the invention, the reactivation of the battery takes place by internally heating the electrolyte, which is achieved with the help of its own time-controlled current via the battery contacts, whereby a negligibly small electric output is transformed in the external circuit. To that end the high internal resistance during supercooling is utilized and works as an internal heating element. A reactive load (X) is advantageously connected to at least one inductive and/or capacitive element through the battery contacts (+,−). During the reactivation a control circuit (CC) periodically switches the reactive load (X) via at least one switch (S1, S2, S3, S4) so that an alternating reactive current (I_L) flows through the battery (B).

Claims

1. A device for reactivating an electrical battery which because of the effect of frost on the inside of the battery is unable to supply the required minimum amount of electric power through battery contacts to a connected consumer unit comprising:

an electronic control circuit which is connected to the battery contacts for heating the inside of the battery by its own battery current through the battery contacts, causing a direct internal heating of the electrolyte such that a minimum of electric output is provided by an external circuit without regard to availability of battery voltage.

2. A device as claimed in claim 1, wherein the external circuit contains at least one switch which is periodically switched by the control circuit during reactivation so that a pulsating battery current flows through the battery, and a capacitor can store battery voltage during blocking.

3. A device as claimed in claim 1, wherein the external circuit contains a reactive load with at least one inductive and/or capacitive element, whose connectors are periodically switched by the control circuit during reactivation by at least one switch, so that an alternating reactive current flows through the battery.

4. A device as claimed in claim 3, wherein the reactive load is an inductance with a parallel resonance capacity, which is periodically switched to the battery contacts by a series switch, where a diode lies parallel to the switch and is located in a blocking direction of the battery voltage.

5. A device as claimed in claim 3, wherein the switches form a push-pull bridge circuit which connects the reactive load connectors crosswise to the battery contacts with alternating current, so that a sawtooth-shaped alternating current flows through them, where its current peaks are at least below the short circuit current of the battery when it is not supercooled.

6. A device as claimed in claim 5, wherein the reactive load (X) is an inductance.

7. A device as claimed in claim 1, wherein to protect an operative battery against too high a load caused by current peaks, the size of an inductance in relation to the pulse frequency and/or keying ratio is chosen so that the current peaks are at least below the short-circuit current of the battery when it is not supercooled.

8. A device as claimed in claim 4, wherein a size of the inductance in relation to the pulse frequency and/or keying ratio is chosen so that a supercooled battery is charged with current peaks at or near the level of the short-circuit current.

9. A device as claimed in claim 1, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

10. A device as claimed in claim 3, the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by a temperature sensor in order to end the reactivation or prevent an operative battery from being reactivated.

11. A device as claimed in claim 6, wherein to protect an operative battery against too high a load caused by current peaks, the size of an inductance in relation to the pulse frequency and/or keying ratio is chosen so that the current peaks are at least below the short-circuit current of the battery when it is not supercooled.

12. A device as claimed in claim 4, wherein the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by a temperature sensor in order to end the reactivation or prevent an operative battery from being reactivated.

13. A device as claimed in claim 5, wherein the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by a temperature sensor in order to end the reactivation or prevent an operative battery from being reactivated.

14. A device as claimed in claim 6, wherein the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by means of a temperature sensor (TS) in order to end the reactivation or prevent an operative battery from being reactivated.

15. A device as claimed in claim 7, wherein the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by a temperature sensor in order to end the reactivation or prevent an operative battery from being reactivated.

16. A device as claimed in claim 8, wherein the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by a temperature sensor (TS) in order to end the reactivation or prevent an operative battery from being reactivated.

17. A device as claimed in claim 9, wherein the electronic control circuit evaluates the battery voltage during the current peaks and also monitors heating by a temperature sensor in order to end the reactivation or prevent an operative battery from being reactivated.

18. A device as claimed in claim 6, wherein a size of the inductance in relation to the pulse frequency and/or keying ratio is chosen so that a supercooled battery is charged with current peaks at or near the level of the short-circuit current.

19. A device as claimed in claim 2, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

20. A device as claimed in claim 3, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

21. A device as claimed in claim 4, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

22. A device as claimed in claim 5, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

23. A device as claimed in claim 6, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

24. A device as claimed in claim 7, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.

25. A device as claimed in claim 8, wherein the electronic control circuit adjusts the pulse frequency and/or the keying ratio as a function of the temperature of battery, so as to adapt the intensity of the direct internal heating to the actual conditions without any delay.