Method of rebuilding a rechargeable battery

Abstract

A rechargeable power tool battery is rebuilt by replacing its spent cells with an array of replacement cells in which connections are made by conductive connectors, ends of which are clamped by bent-over arms of star-shaped malleable metal grips, the hubs of which are spot welded to cell terminals by the replacement cell supplier. Replacement cells can be supplied in pairs with the positive terminal of one cell of the pair permanently connected to the negative terminal of the other cell of the pair and with the other positive and negative terminals each provided with a spot-welded star-shaped grip.

What is claimed is: 
     
         1 . A method of rebuilding a rechargeable battery comprising a set of spent, electrically interconnected, electrochemical cells of substantially uniform size within a battery case, the cells being connected to battery terminals on said battery case, each of said cells having a cylindrical shell, a positive terminal at one end of the shell, and a negative terminal at an opposite end of the shell, and said cells being arranged in an array in which the cylindrical shell of each cell is in close proximity to the cylindrical shell of at least one other cell in the array, and in which a first set of ends composed of one end of each of the shells is disposed substantially in a first plane and the remaining ends of the shells are disposed substantially in a second plane parallel to the first plane and spaced from the first plane by a distance substantially equal to the length of each of the shells, the method comprising the steps of:
 removing said set of spent cells from the battery case;   arranging a fresh set of cells in substantially the same arrangement as that of the spent cells, wherein each of a plurality of terminals of cells of the fresh set at the ends of the shells thereof in said first plane is permanently connected to one of a plurality of metal connecting parts before said fresh set of cells is arranged in said arrangement;   establishing electrical interconnections in said fresh set of cells corresponding to the electrical interconnections in said set of spent cells, at least in part by connecting each of said metal connecting parts to another of said metal connecting parts by mechanically securing first and second parts of a conductive connector to respective metal connecting parts to be connected;   enclosing the fresh set of cells within said battery case; and   electrically connecting said fresh set of cells to said battery terminals on said battery case.   
     
     
         2 . The method according  claim 1 , in which each of said plurality of terminals of cells of the fresh set at the ends of the shells thereof in said first plane is permanently connected by welding to one of a plurality of a metal connecting parts before said fresh set of cells is arranged in said arrangement. 
     
     
         3 . A method of rebuilding a rechargeable battery comprising a set of spent, electrically interconnected, electrochemical cells of substantially uniform size within a battery case, the cells being connected to battery terminals on said battery case, each of said cells having a cylindrical shell, a positive terminal at one end of the shell, and a negative terminal at an opposite end of the shell, and said cells being arranged in an array in which the cylindrical shell of each cell is in close proximity to the cylindrical shell of at least one other cell in the array, and in which a first set of ends composed of one end of each of the shells is disposed substantially in a first plane and the remaining ends of the shells are disposed substantially in a second plane parallel to the first plane and spaced from the first plane by a distance substantially equal to the length of each of the shells, the method comprising the steps of:
 removing said set of spent cells from the battery case;   arranging a fresh set of cells in substantially the same arrangement as that of the spent cells, wherein each of a plurality of terminals of cells of the fresh set at the ends of the shells thereof in said first plane is permanently connected to one of a plurality of metal grips before said fresh set of cells is arranged in said arrangement;   establishing electrical interconnections in said fresh set of cells corresponding to the electrical interconnections in said set of spent cells, at least in part by connecting each of said metal grips to another of said metal grips by mechanically securing first and second parts of a conductive connector to respective metal grips to be connected;   enclosing the fresh set of cells within said battery case; and   electrically connecting said fresh set of cells to said battery terminals on said battery case.   
     
     
         4 . The method according  claim 3 , in which each of said plurality of terminals of cells of the fresh set at the ends of the shells thereof in said first plane is permanently connected by welding to one of said plurality of said metal grips before said fresh set of cells is arranged in said arrangement. 
     
     
         5 . The method according  claim 3 , in which said metal grips are star-shaped grips each having a hub and a plurality of arms extending from the hub, and in which the metal grips are mechanically secured to said first and second parts of a conductive connector by positioning the first and second parts respectively in contact with hubs of two star-shaped grips, and bending arms of the grips over said first and second parts, thereby clamping each of said first and second parts of the conductive connector between arms of a star-shaped grip and a hub thereof. 
     
     
         6 . The method according  claim 5 , in which each of said plurality of terminals of cells of the fresh set at the ends of the shells thereof in said first plane is permanently connected by welding to one of said plurality of said metal grips before said fresh set of cells is arranged in said arrangement.