Rechargeable battery pack and method for manufacturing same

A rechargeable battery pack, said rechargeable battery pack having:

• a housing;
• a cell cluster, said cell cluster including:
• a cell array formed from at least three rechargeable cells, each said cell having:
• a conductive case that defines a cell base and a cell side wall;
• and a head, separate from said case, that is located opposite said base, wherein said case includes a lip that extends around said head and said case, including said base, forms a first terminal of said cell and said head forms a second terminal of cell and said cells are arranged together side-by-side to form said cell array and are oriented so that the bases of two said cells and the head of an at least one remaining said cell form a first end of said cell array and the heads of said two cells and the base of said at least one remaining cell form a second end of said cell array, and said each said cell abuts at least one other said cell;
• a plurality of insulating sleeves, each said insulating sleeve extending around said side wall of a separate said cell so that said insulating sleeves insulate said cell cases from each other, wherein said insulating sleeves are disposed over said cell cases so as to leave said bases and said lips of each said cell at least partially exposed;
• two binders, each said binder being formed from flat, electrically insulating material and being disposed over a separate one of said ends of said cell array, each said binder being adhesively bonded to said cell bases and case lips over which said binder is disposed to secure said cells together, each said binder being formed with a plurality of openings, each opening exposing one of said cell bases or said heads wherein, said binders are formed with sections that subtend said case lips;
• a plurality of conductive straps for electrically, series connecting said cells together, each said strap extending from a cell base, through one said binder opening, over said binder, through a second binder opening and to a cell head adjacent said cell base;
• and
• two conductive terminals, each said terminal extending from a cell head or a cell base through a binder opening;
• and
• conductive contacts secured to said housing, said conductive contacts being electrically connected to said conductive terminals of said cell cluster to establish an electrical path from said conductive contacts to said cells.

A rechargeable battery pack, comprising:

• a cell cluster, said cell cluster including:
• a cell array formed from a plurality of rechargeable cells, each said cell having:
• a conductive case that is shaped to define a base, a side wall that extends upwardly form said base that has an upper end distal from said side wall, wherein said case is a first conductive terminal of said cell;
• and a head secured to said case adjacent said upped end of said side wall, wherein said head is electrically insulated from said case and functions as a second conductive terminal of said cell and wherein said cells are positioned together so that said case side wall of at least one cell abuts a case side wall of a second cell;
• an insulating sleeve adhesively secured to each said case side wall to electrically insulate said abutting case side walls from each other, each said insulating sleeve formed from an electrically insulating tape that is adhesively secured to said case side wall with which said sleeve is associated;
• a binder secured over said cells, said binder being formed from electrically insulating material and adhesively secured over one end of said cells so as to secure said cells together, said binder being formed with openings that expose the heads of said cells subtended by said binder, wherein each said binder opening is defined by a section of said binder that subtends said case upper end;
• and
• a conductive strap for electrically connecting a head of a first said cell to an adjacent end of a second said cell, said conductive strap extending from said binder opening through which said head of said first cell is exposed, over said binder and into said binder opening through which said end of said second cell is exposed;
• a housing having an enclosure in which said cell cluster is contained;
• and
• conductive contacts that are mounted to said housing and electrically connected to said cells.

A method of assembly a cell cluster, said method including the steps of:

• providing a plurality of rechargeable cells, each cell having:
• a case that defines a base which functions as one end of the cell, a side wall that extends upwardly from the base, the side wall having an upper end located distal from said base;
• and a head mounted to the case so as to function as a second end of the cell, wherein the upper end of the side wall extends around an outer perimeter of the cell head and the case and the cell head function as separate electrical terminals of the cell;
• arranging the cells in a side-by-side arrangement so that the side wall of each cell abuts the side wall of another cell and the cells form a cell array that has opposed ends formed from the opposed ends of the cells;
• securing a planar, electrically insulating binder over at least one end of the cell array that has at least one cell head, wherein the binder secures the cells together and the binder is formed to define openings that at least partially expose the ends of the cells and the portion of the binder that defines the opening that exposes the cell head covers the upper end of the cell side wall associated with the exposed cell head;
• and
• electrically connecting the cell head to the end of adjacent cells by securing a conductive strap between the cell head and the adjacent cell end, wherein the strap extends from a first binder opening, over the binder and into a second binder opening.