Patent ID: 6143439
Filing Date: 2000-11-07
Classification: H01M,Y02E

Abstract:
In an electrochemical cell having an open ended cylindrical housing and an end cap assembly inserted therein closing said housing, said cell having a positive and a negative terminal and a label around the cell housing, said end cap assembly comprising a terminal end cap and an electrically insulating sealing member, said sealing member having an elongated electrically conductive current collector passing therethrough, the current collector being in electrical contact with the end cap and the sealing member electrically insulating the end cap from said housing, and the edge of said housing being crimped over the peripheral edge of said end cap to form a cell shoulder along the line of crimp, the improvement comprising:said end cap having a portion of its surface flat and at about right angle to the cell's longitudinal axis and at about the same level as said cell shoulder, said flat surface providing an electrical contact region for an electrically conductive layer of a condition tester for the cell;wherein at least a portion of said tester is attached to the inside surface of said label; wherein said flat portion of said terminal end cap forms an annular step; wherein said terminal end cap has a depressed central region and an upwardly deflecting annular surface extending from the edge of said central region at an angle of between about 1 and 20 degrees from horizontal as measured when said cell is in vertical position with said end cap at top; and wherein said annular step is located between said upwardly deflecting surface and the peripheral edge of said end cap; wherein said terminal end cap surface is contoured to provide a raised annular rib located between said upwardly extending surface and said step wherein said raised rib forms the highest point on said terminal end cap when said cell is oriented in vertical position with said end cap at the top, wherein said step is located below said raised rib.