Battery pack assembly

• US 20050271934A1
• Filed: 06/05/2004
• Published: 12/08/2005
• Est. Priority Date: 06/05/2004
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Kiger, William B., Maggert, Kevin K.
• Application Number:
  US10/861,143
• Publication Number:
  US 20050271934A1
• Time in Patent Office: Days
• US Class Current: 429/159
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: H01M 50/519 comprising printed circuit boards [PCB]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A low-profile battery pack having an electrolyte barrier is provided. The pack includes a plurality of rechargeable cells, being arranged in end to end pairs of two cells. A cleavage void formed by the convex geometry of the cells accommodates at least one insulator and a first circuit board. Tabs couple the cells to the first circuit board. A flexible substrate couples the first circuit board to a second circuit board. The assembly is then placed in a housing having a first compartment and a second compartment, such that the cells are placed in the first compartment and the second circuit board is placed in the second compartment. Between the first and second compartments exists an electrolyte barrier. The flexible substrate passes through an opening in the electrolyte barrier. Adhesive placed in the opening, about the flexible substrate, ensures a seal that keeps electrolyte that may appear in the first chamber from passing to the second chamber. The overall battery pack is both compact in size and robust in performance.

Claims

1. A multi-cell battery pack, comprising:

a. a plurality of cylindrical cells, wherein when two of the cylindrical cells are adjacent, a cleavage space exists between a line at which the two cells touch and a plane tangent to the two cells;

b. an insulator disposed within the cleavage space;

c. a first circuit board disposed atop the insulator, such that the first circuit board sits within the cleavage space, the first circuit board comprising at least one aperture;

d. a flexible circuit having a first end and a second end, the first end being coupled to the first circuit board;

e. a second circuit board coupled to the second end of the flexible circuit; and

f. a plurality of tabs coupling the plurality of cells to the first circuit board, wherein at least one of the tabs passes through the at least one aperture.

2. The circuit of claim 1, further comprising at least one tab connection plate electrically coupled to the first printed circuit board.

3. The circuit of claim 1, further comprising a housing having a first and a second chamber, wherein the plurality of cells are disposed in the first chamber, and the second circuit board is disposed in the second chamber.

4. The circuit of claim 3, wherein the first chamber and second chamber are separated by a water-tight seal.

5. The circuit of claim 4, wherein the flexible circuit passes through the water-tight seal.

6. A battery pack, comprising:

a. at least two cells, the cells each having an exterior casing with a convex curvature, wherein when the at least two cells are placed next to each other a cleavage void exists between the convex curvatures;

b. an insulator having at least two concave curvatures, the insulator being disposed within the cleavage void such that the at least two concave curvatures mechanically mate with the convex curvatures;

c. a plurality of tabs coupled to the at least two cells;

d. a first printed circuit board disposed atop the insulator, the first printed circuit board comprising at least one aperture;

e. a plurality of tab connection plates disposed on the printed circuit board;

f. a flexible substrate having a first end, the first end being coupled to the first printed circuit board;

g. a second printed circuit board, the second printed circuit board being coupled to a distal end of the flexible substrate; and

h. a housing, the housing comprising a main cavity and sealing chamber, wherein the second printed circuit board is disposed within the sealing chamber, further wherein the at least two cells are disposed in the main cavity.

7. The pack of claim 6, wherein at least one of the plurality of tabs passes through the at least one aperture.

8. The pack of claim 7, wherein the at least one of the plurality of tabs is coupled to at least one of the plurality of tab connection plates.

9. The pack of claim 8, wherein the coupling of the at least one of the plurality of tabs to the at least one of the plurality of tab connection plates is a weld.

10. The pack of claim 6, wherein the housing comprises an opening connecting the main cavity and the sealed chamber, wherein the flexible substrate passes through the opening.

11. The pack of claim 10, wherein the opening is filled with an adhesive about the flexible substrate.

12. The pack of claim 6, wherein a thermistor is coupled to the first printed circuit board.

13. The pack of claim 6, wherein charging circuitry is coupled to the second printed circuit board.

14. A battery pack for a portable electronic device, comprising:

a. at least six cylindrical cells, the at least six cylindrical cells being arranged within a housing in three pairs of two cylindrical cells, the three pairs of two cylindrical cells being arranged end to end;

b. at least three insulators, where one of the at least three insulators is disposed within a wedge area existing between one of the three pairs of two cylindrical cells;

c. a first circuit board, the first circuit board having a length greater than a length of two pairs of the three pairs two cylindrical cells, the two pairs being aligned end to end, wherein the first circuit board comprises at least two apertures;

d. a plurality of tabs coupling the at least six cylindrical cells to the first circuit board, wherein at least two tabs of the plurality of tabs pass through the at least two apertures; and

e. a flexible circuit coupled to the first circuit board.

15. The pack of claim 14, further comprising a second circuit board coupled to the flexible circuit.

16. The pack of claim 15, wherein the housing comprises a first and second compartment, the at least six cylindrical cells residing in the first compartment, and the second circuit board residing in the second compartment.

17. The pack of claim 16, wherein the first and second compartments are separated by a barrier that prevents liquid in the first chamber from passing to the second chamber.

18. The pack of claim 17, wherein the flexible circuit passes through the barrier.