ADDITIONAL BATTERY PACK

• US 20150207346A1
• Filed: 12/26/2014
• Published: 07/23/2015
• Est. Priority Date: 01/20/2014
• Status: Abandoned Application

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: TOIVOLA, Timo Tapani, KARI, Juhani
• Application Number:
  US14/583,438
• Publication Number:
  US 20150207346A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034

Abstract

The invention relates to an apparatus comprising an autobalancing circuit that is configured to be electrically connected to a first battery and a second battery. The autobalancing circuit is configured to determine voltage difference Vbat1−Vbat2 between the output voltage of the first battery Vbat1 and the output voltage of the second battery Vbat2. If the voltage difference Vbat1−Vbat2 is higher than a predetermined limiting voltage, the autobalancing circuit is configured to limit balancing current between the first battery and the second battery until the output voltage difference is less than the predetermined limiting voltage. The invention further relates to a method and a mobile device comprising the apparatus.

Claims

1. An apparatus comprising:

a cover for a mobile device;

an autobalancing circuit attached to the cover, wherein the autobalancing circuit is configured to be electrically connected to a first battery and a second battery, wherein the second battery is attached to the cover, and wherein the autobalancing circuit is configured to determine voltage difference Vbat1−

Vbat2 between the output voltage of the first battery Vbat1 and the output voltage of the second battery Vbat2, and if the voltage difference Vbat1−

Vbat2 is higher than a predetermined limiting voltage, the autobalancing circuit is configured to limit balancing current between the first battery and the second battery until the output voltage difference Vbat1−

Vbat2 between the first battery and the second battery is less than the predetermined limiting voltage.

2. An apparatus according to claim 1, wherein the autobalancing circuit is configured to limit the balancing current by connecting the batteries in parallel through a limiting resistor.

3. An apparatus according to claim 1, wherein the autobalancing circuit is configured to couple the batteries in parallel directly if the output voltage difference Vbat1−

Vbat2 is determined to be less than the predetermined limiting voltage.

4. An apparatus according to claim 1, wherein the first battery is a main battery of a mobile device and the second battery is an additional battery for the mobile device.

5. An apparatus according to claim 1, wherein the cover is a replaceable cover for the mobile device.

6. A method, comprising:

determining voltage difference Vbat1−

Vbat2 between an output voltage of a first battery Vbat1 and an output voltage of a second battery Vbat2 by an autobalancing circuit, wherein the autobalancing circuit is configured to be electrically connected to the first battery and the second battery, and wherein the second battery and the autobalancing circuit are attached to a cover for a mobile device; and

limiting balancing current between the first battery and the second battery until the output voltage difference Vbat1−

Vbat2 between the first battery and the second battery is less than the predetermined limiting voltage, if the voltage difference Vbat1−

Vbat2 is higher than a predetermined limiting voltage.

7. A method according to claim 6, wherein the autobalancing circuit is configured to limit the balancing current by connecting the batteries in parallel through a limiting resistor.

8. A method according to claim 6, wherein the method further comprises connecting the batteries in parallel directly, if the output voltage difference Vbat1−

Vbat2 is determined to be less than the predetermined limiting voltage.

9. A computer program product embodied on a non-transitory computer readable medium, comprising computer program code configured to, when executed on at least one processor, cause an apparatus to:

determine voltage difference Vbat1−

Vbat2 between an output voltage of a first battery Vbat1 and an output voltage of a second battery Vbat2, wherein an autobalancing circuit is configured to be electrically connected to the first battery and the second battery, and wherein the second battery and the autobalancing circuit are attached to a cover for a mobile device; and

limit balancing current between the first battery and the second battery until the output voltage difference Vbat1−

Vbat2 between the first battery and the second battery is less than the predetermined limiting voltage, if the voltage difference Vbat1−

Vbat2 is higher than a predetermined limiting voltage.

10. A computer program product according to claim 9, wherein the apparatus is caused to limit the balancing current by connecting the batteries in parallel through a limiting resistor.

11. A computer program product according to claim 9, wherein the apparatus is caused to couple the batteries in parallel directly if the output voltage difference Vbat1−

Vbat2 is determined to be less than the predetermined limiting voltage.