Apparatus and method for managing power of battery packs in a portable device

• US 7,839,121 B2
• Filed: 03/16/2007
• Issued: 11/23/2010
• Est. Priority Date: 03/20/2006
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Yang Hoon
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Berhanu; Samuel
• Application Number:
  US11/687,423
• Publication Number:
  US 20070216355A1
• Time in Patent Office: 1,348 Days
• Field of Search: 320124-125, 320/128
• US Class Current: 320/124
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit

Abstract

To manage power of battery packs, charging currents and remaining capacities of the battery packs may be detected. An order for charging and discharging the battery packs may be determined based on the charging currents. The battery packs may be charged or discharged in the determined order based on whether an external voltage is detected. The battery packs may be charged using charging voltages with associated currents corresponding to the detected charging currents.

Claims

1. An apparatus for managing power in a portable device, comprising:

a control module configured to;

determine a remaining capacity and a charging current from each of a first battery pack and a second battery pack coupled to a portable device,

determine an order for charging and discharging the first and second battery packs based on the charging currents,

output a battery selection signal that selects one of the first battery pack and the second battery pack based on the determined order,

output a charge mode signal indicating one of a charging mode and a discharging mode based on a presence of an external voltage, and

generate a charging control signal corresponding to the remaining capacity and the charging current of the selected battery pack;

a charging voltage module configured to convert, based on the charging control signal, the external voltage into a charging voltage with a current capacity; and

a path setting module coupled to the charging voltage module, the first and second battery packs, and a system load in the portable device, the path setting module configured to supply the charging voltage from the charging voltage module to the selected battery pack or supply output voltage from the selected battery pack to the system load according to the charge mode signal and the battery selection signal.

2. The apparatus of claim 1, wherein the determined order indicates charging and discharging of the first battery pack prior to the second battery pack when the charging current of the first battery pack exceeds the charging current of the second battery pack.

3. The apparatus of claim 2, wherein the path setting module is configured to supply output voltage from the first battery pack to the system load until a predetermined remaining capacity of the first battery pack is detected by the control module and to subsequently supply output voltage from the second battery pack to the system load.

4. The apparatus of claim 1, wherein each of the first and second battery packs includes cells charged and discharged and a cell watchdog (CEWD) for detecting the remaining capacity and charging current of the cells and outputting the remaining capacity and the charging current in response to a battery state information request signal.

5. The apparatus of claim 1, further comprising an external voltage detector configured to detect external voltage output from an AC adaptor, the external voltage detector interposed between an external voltage input terminal of the charging voltage module and an external voltage detection terminal of the control module.

6. The apparatus of claim 1, wherein the path setting module comprises:

first and second analog switches respectively coupled between an output terminal of the charging voltage module and output terminals of the first and second battery packs and independently activated according to the battery selection signal; and

a third analog switch coupled between a common connection node of the first and second analog switches and the system load and activated according to the charge mode signal.

7. The apparatus of claim 6, further comprising a voltage path controller configured to supply the external voltage to the system load in a one-way direction, the voltage path controller being interposed between an external voltage input terminal of the charging voltage module and an output node of the third analog switch.

8. The apparatus of claim 7, wherein the voltage path controller comprises a diode.

9. The apparatus of claim 7, further comprising:

a DC-DC converter for dropping and stabilizing the external voltage, or a DC voltage supplied from the first and second battery packs, to a resultant voltage level suitable for driving the system load and distributing the resultant voltage to respective parts of the system load, the DC-DC converter being interposed between the voltage path controller and a voltage input terminal of the system load of the portable device.

10. The apparatus of claim 1, further comprising a DC-DC converter for dropping and stabilizing the external voltage, or a DC voltage supplied from the first and second battery packs, to a resultant voltage level suitable for driving the system load and distributing the resultant voltage to respective parts of the system load.

11. The apparatus of claim 10, further comprising:

a capacitor connected in parallel to an output terminal of the DC-DC converter.

12. A method for managing power, comprising:

detecting remaining capacities and charging currents of battery packs electrically coupled to a computing device;

determining an order for charging and discharging the battery packs based on the detected remaining capacities and charging currents;

when an external voltage is supplied to the computing device, charging the battery packs in the determined order using charging voltages with currents corresponding to the detected charging currents; and

when the external voltage is not supplied to the computing device, discharging the battery packs by supplying output voltages from the battery packs to a system load in the determined order based on detected remaining capacities.

13. The method of claim 12, wherein determining an order comprises determining the order for charging and discharging by comparing levels of the detected charging currents.

14. The method of claim 13, wherein determining an order comprises determining to charge or discharge a first battery pack prior to a second battery pack when the detected charging current of the first battery pack exceeds the detected charging current of the second battery pack.

15. The method of claim 14, wherein discharging the battery packs comprises discharging the first battery pack until a predetermined remaining capacity of the first battery pack is detected and subsequently discharging the second battery pack.

16. A method for managing power of at least two smart battery packs, each of the battery packs having cells charged and discharged and each of the battery packs storing battery state information indicating at least a charging current of the cells and a remaining capacity of the cells, the method comprising:

detecting the charging current of each battery pack through data communication with the battery packs;

ordering the battery packs from higher charging current to lower charging current; and

charging or discharging the battery packs according to the ordering and the battery state information, based on whether an external voltage is detected.

17. The method of claim 16, wherein charging or discharging comprises charging the battery packs when the external voltage is detected.

18. The method of claim 17, wherein charging the battery packs comprises supplying charging voltages to the battery packs according to the order, the charging voltages having currents corresponding to the detected charging currents.

19. The method of claim 16, wherein charging or discharging comprises discharging a first battery pack until a predetermined remaining capacity of the first battery pack is detected and subsequently discharging a second battery pack according the ordering.

20. A battery management module, comprising:

means for detecting charging currents of battery packs electrically coupled to a computing device;

means for determining an order for charging and discharging the battery packs based on the detected charging currents;

means for setting one of a charging mode and a discharging mode based on whether an external voltage is detected;

means for supplying charging voltages to the battery packs in the charging mode according to the determined order, each charging voltage having a current capacity corresponding to the detected charging current of the battery pack to which the charging voltage is supplied; and

means for supplying output voltages from the battery packs to a system load in the discharging mode according to the determined order.