Apparatus and method for identifying and charging batteries of different types

• US 6,625,477 B1
• Filed: 06/12/1996
• Issued: 09/23/2003
• Est. Priority Date: 06/12/1996
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Wakefield, Ivan Nelson
• Primary Examiner(s): RAO, ANAND SHASHIKANT
• Application Number:
  US08/668,647
• Time in Patent Office: 2,659 Days
• Field of Search: 455/89, 455/127, 455/90, 455/95, 455/572-574, 323/223, 323/225, 323/268, 323/274, 323/275, 323/325, 323/339, 320/31, 320/13, 320/35, 320/21, 320/29
• US Class Current: 455/572
• 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

An apparatus for identifying batteries of different types is disclosed where each battery includes a positive terminal, a negative terminal, and an identification terminal connected to a tap between two cells of the battery. The apparatus includes a positive contact positioned so as to engage the positive terminal of a battery, a negative contact positioned so as to engage the negative terminal of the battery, an identification contact positioned so as to receive a tap voltage from the identification terminal of the battery indicative of a particular battery type, and a microcomputer connected to the positive, negative, and identification contacts, wherein the microcomputer identifies the particular type of the battery on the basis of where the tap voltage lies with respect to a plurality of specified voltage ranges. The apparatus may also include a circuit connected to the microcomputer, the positive contact, the negative contact, and the identification contact for supplying a charging current to the battery in accordance with a specified charging algorithm applicable to the particular battery type.

Claims

1. A battery pack for a mobile telephone comprising:

(a) a housing;

(b) a battery having a plurality of cells, including at least first and second adjacent cells connected in series, positioned within said housing;

(c) an interface for electrically coupling said battery to said mobile telephone, said interface comprising;

(1) a positive terminal connected to said battery at a first end; and

(2) a negative terminal connected to said battery at a second end;

(d) a first electrical path originating at said positive terminal, passing first through said first cell, then through said second cell, and then terminating at said negative terminal, said first electrical path providing means for powering said mobile telephone;

(e) wherein said interface further comprises an identification terminal connecting to said first electrical path at a tap disposed between said first and second cells and supplying a tap voltage; and

(f) wherein a type of battery positioned within said housing is distinguished by a said tap voltage.

2. The mobile telephone of claim 1, wherein said circuitry compares said tap voltage to a plurality of specified voltage ranges stored in said signal processing circuitry and wherein the maximum number of battery types which can be identified by said signal processing circuit is a function of the number of specified voltage ranges.

3. The mobile telephone of claim 1, wherein said charging algorithms control a charging current to said battery.

4. The mobile telephone of claim 1, wherein said circuitry provides a direct charge path between a current source and a terminal of said battery pack.

5. The mobile telephone of claim 3, said circuitry further comprising:

(a) a current source connected to said negative contact and said positive contact; and

(b) a switching device positioned between said current source and said positive contact.

6. The mobile telephone of claim 5, wherein said signal processing circuit controls the opening and closing of said switching device according to said charging algorithms.

7. The mobile telephone of claim 5, said circuitry further comprising a load positioned between said switching device and said positive contact, wherein a first voltage is defined upstream of said load and a second voltage is defined downstream of said load, said charging current being a function of a difference between said first and second voltages.

8. The mobile telephone of claim 3, said circuitry further comprising a voltage regulator positioned between said positive contact and said microcomputer.

10. The mobile telephone of claim 1, further comprising support means in said main housing for receiving battery packs of substantially similar size and shape.

12. The battery pack of claim 1, said tap being located at a distinct position for each type of battery with respect to said plurality of cells comprising said battery.

13. The battery pack of claim 1, wherein said tap is located between the two cells adjacent to said negative terminal.

14. The battery pack of claim 13, wherein the tap voltage provided by said identification terminal of a four cell battery is approximately one-fourth the voltage of said battery.

15. The battery pack of claim 13, wherein the tap voltage provided by said identification terminal of a two cell battery is approximately one-half the voltage of said battery.

16. The battery pack of claim 1, wherein said battery has a total voltage in a range of approximately three to approximately four volts.

17. The battery pack of claim 1, further comprising a fuse positioned between said battery second end and said negative terminal.

18. The battery pack of claim 17, further comprising a protection circuit located between said fuse and said negative terminal to prevent said battery from exceeding a specified temperature and voltage.

19. The battery pack of claim 1, wherein said battery is rechargeable.

20. The battery pack of claim 19, wherein said battery is among a group including nickel cadmium, nickel metal hydride, and lithium.

21. The battery pack of claim 1, wherein said positive terminal is uniquely positioned with respect to said housing for each particular type of said battery therein.

24. The method of claim 1, further comprising the step of supplying a charging current to said battery in accordance with a charging algorithm in said microcomputer applicable to said particular battery type.

26. The battery pack of claim 1, wherein said battery pack comprises a second electrical path originating at said positive terminal, passing through said first cell, and terminating at said identification terminal via said tap, said second electrical path not including said second cell.

9. A method of identifying different types of batteries disposed in battery packs, the method comprising comprising:

providing a first electrical path in each of said different types of battery packs, said first electrical path originating at a positive terminal, passing through a first battery cell, then through a second battery cell, adjacent to said first cell, and terminating at a negative terminal;

providing an identification terminal connected to said first electrical path at a tap disposed between said first and second cells of each battery;

electrically coupling said positive, negative, and identification terminals of said battery to respective positive, negative, and identification contacts connected to a microcomputer;

detecting, at said identification contact, a tap voltage corresponding to said identification terminal; and

identifying a specific battery type by comparing said detected tap voltage to a plurality of predetermined voltage ranges stored in said microcomputer.

11. The method of claim 9, wherein comparing said detected tap voltage to a plurality of predetermined voltage ranges comprises comparing said detected voltage to at least a first specified voltage range of less than approximately two volts and a second specified voltage range of greater than approximately two volts.

22. A mobile telephone, comprising:

(a) a main housing;

(b) a signal processing circuit located within said main housing for operating said mobile telephone in a particular mode of communication, said signal processing circuit connected to positive, negative, and identification contacts;

(c) a battery pack comprising positive, negative, and identification terminals attached to said main housing for powering said mobile telephone, said battery pack comprising a first electrical path originating at said positive terminal, passing through a first battery cell, then through a second battery cell, and terminating at said negative terminal,

(d) wherein said identification terminal of said battery pack connects to said first electrical path at a tap disposed between said first and second battery cells, said identification terminal supplying a tap voltage;

(e) an interface for electrically coupling said positive, negative, and identification contacts to said respective positive, negative, and identification terminals, battery wherein said identification contact receives said tap voltage from said identification terminal; and

(f) circuitry associated with said signal processing circuit for identifying the particular type of battery in said battery pack from said received tap voltage.

23. The mobile telephone of claim 22, further comprising circuitry associated with said signal processing circuit for charging said battery pack in accordance with a particular charging algorithm applicable to the electrical characteristics of said battery pack.

25. The mobile telephone of claim 22, wherein said battery pack further comprises a second electrical path originating at said positive terminal, passing through said first cell, and terminating at said identification terminal via said tap, said second electrical path not including said second cell.