METHOD AND DEVICE FOR CHARGING A BATTERY AT ELEVATED TEMPERATURES

• US 20080030171A1
• Filed: 08/04/2006
• Published: 02/07/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Aaltonen, Markus, Villefrance, Rasmus
• Granted Patent: US 7,615,968 B2
• Time in Patent Office: Days
• US Class Current: 320/150
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention pertains to a method and device for charging a battery at elevated temperatures. More specifically the present invention pertains to a method and a device capable of using the method to charge a battery at elevated temperatures, comprising by determining a temperature of at least one cell of a battery to be charged, and limiting the charging voltage applied to said battery to a maximum charging voltage in accordance with said determined temperature.

Claims

1. Method for charging a battery at elevated temperatures, comprising:

determining a temperature of at least one cell of a battery to be charged, and

limiting the charging voltage applied to said battery to a maximum charging voltage in accordance with said determined temperature.

2. Method according to claim 1 wherein said maximum charging voltage is controlled according to a function that relates said maximum charging voltage to the determined temperature.

3. Method according to claim 2 wherein said limiting of said maximum charging voltage comprises:

limiting the charging voltage applied to said battery to a first maximum charging voltage at a temperature below a first threshold temperature, and

limiting the charging voltage applied to said battery to a second maximum charging voltage at a temperature above said first threshold temperature,

wherein said second maximum charging voltage is smaller than said first maximum charging voltage.

4. Method according to claim 3, wherein said limiting of said maximum charging voltage comprises:

limiting the charging voltage applied to said battery to said second maximum charging voltage at a temperature above said first threshold temperature and below a second threshold temperature, wherein said second threshold temperature is higher than said first threshold temperature, and

applying no charging voltage to said battery above said second threshold temperature.

5. Method according to claim 1, further comprising detecting a connection to an external power source.

6. Method according to claim 5, further comprising:

determining electric parameters of at least one cell of said battery, and

limiting the charging voltage applied to the battery to a maximum charging voltage to be applied to said battery in accordance with said determined electric parameters.

7. Method according to claim 1, further comprising controlling the charging voltage to achieve a constant charging current in accordance with said determined temperature.

8. Method according to claim 1, wherein the method is executed on a mobile terminal device.

9. Method according to claim 8, wherein the method is executed on a battery of a mobile terminal device.

10. Method according to claim 8, wherein the method is executed on a battery charger of a mobile terminal device.

11. Computer program product for executing a method capable of charging a battery at elevated temperatures, comprising program code sections for carrying out the method of claim 1, when said program is run on a battery, a controller, a processor-based device, a mobile terminal device such as a mobile telephone or on a charger of a mobile terminal device.

12. Computer program product for executing a method capable of charging a battery at elevated temperatures, comprising program code sections for carrying out the method of claim 1, when said program is run on a battery, a controller, a processor-based device, a mobile terminal device such as a mobile telephone or on a charger of a mobile terminal device.

13. Module for charging a battery at elevated temperatures, comprising:

a battery terminal for connecting said module to a battery to be charged,

a power terminal for connecting said module to a power source,

a sensor terminal for connecting a temperature sensor and

a voltage limiter connected to said battery terminal, said power terminal and to said sensor terminal, provided for limiting a battery charging voltage applied to said battery terminal to a maximum charging voltage in accordance with a temperature sensor signal received at said sensor terminal,

wherein said temperature sensor signal represents a temperature of at least one cell of a connected battery.

14. Module according to claim 13, wherein said voltage limiter is configured to limit the charging voltage to said maximum charging voltage according to a function that relates said maximum charging voltage to the received temperature sensor signal.

15. Module according to claim 13, wherein said voltage limiter is configured to

limit a charging voltage applied to said battery to a first maximum at a temperature below a first threshold temperature, and

limit a charging voltage applied to said battery to a second maximum charging voltage at a temperature above said first threshold temperature,

wherein said second maximum charging voltage is smaller than said first maximum charging voltage.

16. Module according to claim 14, wherein said voltage limiter is configured to limit said charging voltage applied to said battery to said second maximum charging voltage at a temperature above said first threshold temperature and below a second threshold temperature, wherein said second threshold temperature is higher than said first threshold temperature, and

apply no charging voltage to said battery above said second threshold temperature.

17. Module according to claim 13, wherein said voltage limiter is configured to detect a connection to an external power source connected to said power terminal.

18. Module according to claim 13, wherein said voltage limiter is configured to detect a connection to a battery to be charged connected to said battery terminal.

19. Module according to claim 17, wherein said voltage limiter is configured to detect a connection to a temperature sensor connected to said temperature sensor terminal.

20. Module according to claim 16, wherein said voltage limiter is configured to determine electric parameters of at least one cell of said battery, and is further configured to limit a charging voltage applied to the battery to a maximum charging voltage in accordance with said determined electric parameters.

21. Mobile terminal device for charging a battery of said mobile terminal device at elevated temperatures, comprising

a battery of said mobile terminal device, having at least one battery cell,

a power terminal for connecting said mobile terminal device to a(n external) power source,

a temperature sensor in thermal contact with at least one of said at least one battery cells, for determining a temperature of at least one of said at least one battery cells, and

a voltage limiter connected to said battery, to said power terminal and to said temperature sensor, for limiting the charging voltage applied to said battery to a maximum battery charging voltage in accordance with a temperature sensor signal from said temperature sensor,

wherein said temperature sensor signal represents a temperature of at least one cell of a connected battery.

22. Mobile terminal device according to claim 21, wherein said voltage limiter is configured to limit the charging voltage applied to said battery to said maximum charging voltage according to a function that relates said maximum charging voltage to the received temperature sensor signal.

23. Mobile terminal device according to claim 21, wherein said voltage limiter is configured to

limit the charging voltage applied to said battery to a first maximum charging voltage at a temperature below a first threshold temperature, and

limit the charging voltage applied to said battery to a second maximum charging voltage at a temperature above said first threshold temperature,

wherein said second maximum charging voltage is smaller than said first maximum charging voltage.

24. Mobile terminal device according to claim 21, wherein said mobile terminal device is a mobile telephone.

25. Mobile terminal device according to claim 21, wherein said mobile terminal device is a battery of a mobile device.

26. Mobile terminal device according to claim 21, wherein said voltage limiter is configured to detect a connection to a temperature sensor connected to said temperature sensor terminal.

27. Mobile terminal device according to claim 25, wherein said voltage limiter is configured to determine electric parameters of at least one cell of said battery, and is further configured to limit the charging voltage applied to said battery to a maximum charging voltage in accordance with said determined electric parameters.