Method and apparatus for controlling a charging current of a battery in a portable chargeable electronic unit

• US 5,668,462 A
• Filed: 05/08/1995
• Issued: 09/16/1997
• Est. Priority Date: 05/08/1995
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hansson, H. Magnus, Lindquist, Bjorn Martin Gunnar
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/436,831
• Time in Patent Office: 862 Days
• Field of Search: 320/12, 320/2, 320/5, 320/21, 320/30, 320/39, 320/40, 320/48
• US Class Current: 320/110
• CPC Class Codes: H02J 7/00038 using passive battery identification means, e.g. resistors or capacitors identification by mechanical connections H02J7/0045
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries

Abstract

A battery charger charges a battery in a portable chargeable electronic device, such as a cellular phone, with a long-term-constant current, even while the device is used. The charging current is controlled by circuitry in the portable device, avoiding the need for control circuitry in the battery charger or battery. A battery-charger connector that corresponds to the type of battery in the portable device is keyed to fit only a charger that matches the type of battery, thus assuring proper charging of the battery. Alternatively, a simple contact connects the battery charger to the battery. A belt clip covers the battery-charger connector when the battery charger is disconnected to prevent short-circuiting the battery.

Claims

1. A method of controlling a charging current of a battery in a portable chargeable electronic unit, including the steps of:

delivering a charging current from a battery charger to the battery in the portable chargeable electronic unit; and

directly controlling flow of the charging current using control logic in the portable chargeable electronic unit.

2. The method of claim 1, wherein the portable chargeable electronic unit is a mobile communication unit.

3. The method of claim 1, wherein one of an AC/DC converter and a DC/DC converter is used as the battery charger.

4. The method of claim 1, wherein the charging current is delivered through different battery-charger connectors for different types of batteries.

5. The method of claim 1, wherein the charging current is delivered from the battery charger to the battery through a contact.

6. The method of claim 5, wherein the contact is covered by a clip.

7. The method of claim 1, wherein the controlling step includes the steps of switching the charging current delivered from the battery charger on and off.

8. The method of claim 7, wherein the charging current is switched on and off such that a long-term-constant current is obtained.

9. The method of claim 1, wherein the controlling step includes the step of sensing a current level of the charging current delivered from the battery charger.

10. The method of claim 1, wherein the controlling step includes the steps of:

sensing a current level of the charging current delivered from the battery charger; and

switching the charging current delivered from the battery charger on and off based on the sensed current level.

11. An apparatus for controlling a charging current of a battery in a portable chargeable electronic unit, comprising:

means for delivering a charging current from a battery charger to the battery in the portable chargeable electronic unit;

means, comprising a control logic circuit in the portable chargeable electronic unit, for directly controlling flow of the charging current.

12. The apparatus of claim 11, wherein the portable chargeable electronic unit is a mobile communication unit.

13. The apparatus of claim 11, wherein the battery charger is one of an AC/DC converter and a DC/DC converter.

14. The apparatus of claim 11, wherein the delivering means comprises different battery connectors for corresponding different types of batteries.

15. The apparatus of claim 11, wherein the delivering means is a contact.

16. The apparatus of claim 15, wherein the contact is covered by a clip.

17. The apparatus of claim 11, wherein the controlling means includes means for switching the charging current delivered from the battery charger on and off.

18. The apparatus of claim 17, wherein the switching means switches the charging current on and off to obtain a long-term-constant current.

19. The apparatus of claim 11, wherein the controlling means includes means for sensing a level of the charging current delivered from the battery charger.

20. The apparatus of claim 11, wherein the controlling means includes:

means for sensing a level of the charging current delivered from the battery charger; and

means for switching the charging current delivered from the battery charger on and off based on the level sensed by the sensing means.

21. An apparatus for controlling a charging of a battery adapted to connect to a portable chargeable electronic unit, comprising:

means, in the portable chargeable electronic unit, for delivering a charging current from a battery charger to the battery; and

means, comprising a control logic circuit in the portable chargeable unit, for directly controlling flow of the charging current from the battery charger.