METHOD AND APPARATUS FOR CHARGING A BATTERY USING MULTIPLE CHARGING SOURCES

• US 20140152234A1
• Filed: 11/30/2012
• Published: 06/05/2014
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Herrmann, John E., Kerfoot, Roy L. Jr., Herrmann, Amy T., Louie, Edmond
• Granted Patent: US 9,496,738 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage

Abstract

Embodiments include a modular battery charger having a main charging source and is configured to include at least one additional charging source that can be an auxiliary charging source or an external charging source. The additional charging sources can be added as modules to augment the total charging current that can be provided to a rechargeable battery. The modular battery charger can selectively enable or disable the additional charging sources while controlling the output current of the main charging source to adjust the charging current provided to a rechargeable battery.

Claims

1. A modular battery charger, comprising:

a main charging source that provides a main charging current to a charging interface, the charging interface configured to connect to a rechargeable battery;

an auxiliary charging source that selectively provides auxiliary charging current to the rechargeable battery; and

a charge controller operably coupled to the main charging source to control the main charging current provided to the charging interface, and further operably coupled to the auxiliary charging source to enable or disable the auxiliary charging source.

2. The modular battery charger of claim 1, wherein the auxiliary charging source is operable from a vehicular DC power source.

3. The modular battery charger of claim 1, wherein the auxiliary charging source is coupled to the charging interface through a switch that is operated by the charge controller.

4. The modular battery charger of claim 1, wherein the charging interface connects to a set of charging contacts of the rechargeable battery, the auxiliary charging source connects to a positive device contact of a set of device contacts.

5. The modular battery charger of claim 1, further comprising an external charging source interface that accepts an external charging source module that provides additional charging current to the rechargeable battery, the external charging source interface configured to allow the charge controller to selectively enable or disable the external charging source module when connected to the external charging source interface.

6. The modular battery charger of claim 5, wherein the external charging source interface has a negative contact that is coupled to a negative device contact of the set of device contacts.

7. The modular battery charger of claim 5, wherein the external charging source interface is further coupled to the charging interface to provide additional charging current to the rechargeable battery.

8. The modular battery charger of claim 7, wherein the external charging source interface is coupled to the charging interface through a switch, wherein the switch is operated by the charge controller.

9. The modular battery charger of claim 5, wherein the external charging source interface has a negative contact that is coupled to a negative contact of the charging interface.

10. The modular battery charger of claim 9, wherein current provided by both the main charging source and the auxiliary charging source passes through sense resistance that is monitored by the charge controller.

11. The modular battery charger of claim 5, wherein the auxiliary charging source and the external charging source interface have a common ground, the main charging source uses a main ground, and wherein the common ground and main ground are different.

12. A method of operating a battery charger having a main charging source and an auxiliary charging source, comprising:

detecting a battery being electrically connected to the battery charger;

determining that the battery can be charged with a charging current greater than can be supplied by the main charging source alone;

in response to determining that the battery can be charged with a charging current greater than can be supplied by the main charging source alone, enabling the auxiliary charging source to source an auxiliary current to the rechargeable battery; and

in response to enabling the auxiliary charging source, increasing a current provided by the main charging source until either a maximum total current of the main charging source and the auxiliary charging source, a maximum battery voltage, or a maximum current of the main charging source is reached.

13. The method of claim 12, wherein determining that the battery can be charged with a charging current greater than can be supplied by the main charging source comprises reading information from the rechargeable battery that indicates that the battery can be charged with a charging current greater than can be supplied by the main charging source.

14. The method of claim 12, wherein determining that the battery can be charged with a charging current greater than can be supplied by the main charging source comprises applying current from the main charging source and increasing the current from the main charging source to the maximum current of the main charging source and determining that additional current can be provided without exceeding a maximum charge current of the rechargeable battery.

15. The method of claim 12, further comprising:

connecting an external charging source to the battery charger; and

enabling the external charging source to provide current to the rechargeable battery.

16. The method of claim 12, further comprising:

determining that a voltage of the rechargeable battery has reached an upper limit;

maintaining the battery voltage at the upper limit by ramping down current provided by the main charging source until the current provided by the main charging ramps down to a lower limit; and

in response to the current provided by the main charging source ramping down to the lower limit, shutting off the auxiliary charging source, then ramping up the current provided by the main charging source until the battery voltage is at the upper limit, then ramping the current provided by the main charging source down to maintain the battery voltage at the upper limit.

17. A battery charger, comprising:

a main charging source coupled to a charging interface to provide a main charging current to a rechargeable battery;

an auxiliary charging source that selectively provides an auxiliary charge current to the rechargeable battery in addition to the main charging current; and

a charge controller operably coupled to the main charging source that controls the charging current, the charge controller further coupled to the auxiliary charging source to enable or disable the auxiliary charging source, wherein the charge controller detects connection to a rechargeable battery and enables the auxiliary charging source to provide the auxiliary charge current to the rechargeable battery if rechargeable battery can be recharged with a current that is greater than a maximum current that can be supplied by the main charging source.

18. The battery charger of claim 17, further comprising:

an external charging source connected to an external charging source interface of the battery charger that selectively provides an external source current to the rechargeable battery; and

wherein the charge controller further determines that the rechargeable battery can be charged at a rate that is greater than the sum of the auxiliary charge current and the maximum current that can be provided by the main charging source.

19. The battery charger of claim 17, wherein the auxiliary charge current is provided to the rechargeable battery through a switch that is controlled by the charge controller, where the charger controller can open or close the switch.

20. The battery charger of claim 17, wherein the auxiliary charge current is provided to the rechargeable battery through a positive device contact, and wherein the main charging current is provided to the rechargeable battery through a charging contact of the rechargeable battery.