METHOD AND APPARATUS FOR SELF-HEATING OF A BATTERY FROM BELOW AN OPERATING TEMPERATURE

• US 20160043447A1
• Filed: 08/07/2014
• Published: 02/11/2016
• Est. Priority Date: 08/07/2014
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: KRISHNAMURTHI, MACWIEN, PEH, TEE HOWE, CHE AT, MODH HISHAM MUDDIN BIN, KHOO, KAH KHENG, LOW, POH HUAT
• Granted Patent: US 9,509,152 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/63 Control systems charging or discharging in response to temperature H01M10/44 , H01M10/443; measurement of temperature H01M10/48 , H01M10/486
• CPC Class Codes: H01M 10/6571 Resistive heaters arrangements for heating the battery by its resistance to the internal current H01M10/637
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method and apparatus for a self-heating battery pack uses a battery cells of a first battery cell circuit to power a device. However these battery cells become substantially inoperative below a very cold temperature, so a second battery cell circuit, having a second type of battery cells which can operate at the cold temperature, is used to power a heating element to warm up the first battery cells to a temperature at which they can operate.

Claims

1. A self-heating battery pack, comprising:

a first battery cell circuit including at least one battery cell of a first chemistry, and having a positive terminal coupled to a positive device contact and a negative terminal coupled to the negative device contact, and which is rendered substantially inoperative when below a minimum operating temperature;

a heating circuit including a second battery cell circuit comprised of at least one battery cell of a second chemistry that is operable below the minimum operating temperature of the first battery cell circuit, the heating circuit further including a heating element that is located in proximity to the first battery cell circuit and which is powered by the second battery cell circuit;

a temperature control circuit that senses a temperature of the first battery cell circuit and enables the heating circuit the temperature is below a lower temperature threshold and disables the heating circuit when the temperature is above an upper threshold, and which is enabled by a signal from the auxiliary device contact.

2. The self-heating battery pack of claim 1, wherein the heating element is a nichrome element.

3. The self-heating battery pack of claim 1, wherein the at least one battery cell of the first chemistry is at least one lithium-based battery cell.

4. The self-heating battery pack of claim 1, further comprising:

a set of device contacts for interfacing with a device to be powered by the self-heating battery pack, and including a positive device contact, a negative device contact, and an auxiliary device contact; and

a set of charging contacts for interfacing with a battery charger including a first positive charger contact for charging the at least one cell of the first chemistry, a second positive charger contact for charging the at least one cell of the second chemistry, a negative charger contact, and a thermistor contact.

5. The self-heating battery pack of claim 4, wherein the thermistor contact is coupled to a thermistor that is in thermal proximity to second battery cell circuit.

6. The self-heating battery pack of claim 4, wherein the thermal control circuit is only enabled by a voltage received at the auxiliary device contact.

7. The self-heating battery pack of claim 6, further comprising a switch transistor coupled to the thermal control circuit, between the thermal control circuit and the negative device contact, wherein the switch transistor is responsive to the signal received at the auxiliary device contact to connect the thermal control circuit to the negative device contact upon receiving the signal received at the auxiliary device contact.

8. The self-heating battery pack of claim 1, further comprising a plurality of diodes connected in series, wherein the series-connected plurality of diodes are connected in further series between a second positive contact and the at least one battery cell of the second chemistry.

9. A method of operating a self-heating battery pack, comprising:

enabling a temperature control circuit;

determining, by the temperature control circuit, that a temperature of a first battery cell circuit is below a lower temperature threshold;

in response to determining that the first battery cell circuit is below the lower temperature threshold, the temperature control circuit enabling discharge of a second battery cell circuit through a resistive heating element that is in thermal proximity to the first battery cell circuit; and

subsequent to the enabling discharge of the second battery cell circuit through the resistive heating element, disabling discharge of the second battery cell circuit when the temperature of the first battery cell circuit is above an upper temperature threshold.

10. The method of claim 9, wherein determining that the temperature of the first battery cell circuit is below the lower temperature threshold and above the upper temperature threshold is performed using a thermistor that is in thermal proximity to the first battery cell circuit.

11. The method of claim 9, wherein enabling and disabling discharge of the second battery cell circuit through the resistive heating element is performed the turning on and off, respectively, a transistor switch connected in series with the resistive heating element between the second battery cell circuit and a ground.

12. The method of claim 9, wherein enabling the temperature control circuit comprises:

connecting the self-heating battery pack to a device to be powered by the self-heating battery pack; and

providing a voltage from the first battery cell circuit to a switch connected between the temperature control circuit and either a ground or a power source through the device via an auxiliary contact of the device.

13. The method of claim 12, wherein providing the voltage from the first battery cell circuit via the auxiliary contact comprises providing the voltage via a data contact which is further connected to a data storage device in the self-heating battery pack.

14. The method of claim 9, further comprising, subsequent to disabling the discharge of the second battery cell circuit through the resistive heating element, re-enabling discharge of the second battery cell circuit through the resistive heating element upon the temperature of the first battery cell circuit falling below the lower temperature threshold.

15. A battery pack for a portable two-way radio device, comprising:

a set of charger contacts for connecting the battery pack to a charger and including a first positive charger contact and a second positive charger contact;

a set of device contacts for electrically connecting the battery pack to a device, and including a positive device contact, a negative device contact, and an auxiliary contact;

a first battery cell circuit including at least one battery cell of a first chemistry, and having a positive terminal coupled to the positive device contact and the negative terminal coupled to the negative device contact, and which is rendered substantially inoperative when below a minimum operating temperature;

a charging protection diode connected between the positive terminal of the first battery cell circuit and the first positive charger contact;

a second battery cell circuit comprised of at least one battery cell of a second chemistry that is operable below the minimum operating temperature of the first battery cell circuit;

a resistive heating element that is located in proximity to the first battery cell circuit and which is connected to the second battery cell circuit;

a temperature control circuit that senses a temperature of the first battery cell circuit and discharges the second battery cell circuit through the resistive heating element when the temperature of the first battery cell circuit is below a lower temperature threshold and disables discharge of the second battery cell circuit through the resistive heating element when the temperature of the first battery cell circuit is above an upper threshold.

16. The battery pack of claim 15, wherein the resistive heating element is a nichrome element.

17. The battery pack of claim 15, wherein the at least one battery cell of the first chemistry is at least one lithium-based battery cell.

18. The battery pack of claim 15, wherein set of charger contacts further includes a thermistor contact that is coupled to a thermistor in the battery pack that is in thermal proximity to second battery cell circuit.

19. The battery pack of claim 15, wherein the temperature control circuit is only enabled by a voltage received at the auxiliary device contact.

20. The pack of claim 15, further comprising a plurality of diodes connected in series, wherein the series-connected plurality of diodes are connected in further series between the second positive charger contact and the second battery cell circuit.