20 the mounting flange of the contact cap 22 and the insulator 24 to hold these elements onto the plate 16 as can be seen in fig1 the insulator 24 is arranged to insure that there will be no contact between the annular compression ring 26 and the contact cap 22 a nonconductive seal 28 is positioned about the cap assembly 14 the seal 28 may be of polypropylene the seal 28 includes a central cylindrical portion 30 positioned at the plate 16 about the terminal 18 the seal 28 also includes a radially extending portion 32 which extends outwardly on the inner side of the plate 16 to its periphery a peripheral cylindrical portion 34 extends upwardly about the periphery of the plate 16 outwardly of the annular compression ring 26 the peripheral cylindrical portion 34 extends up far enough such that it prevents the possibility of contact between the annular compression ring 26 and the container 10 thus the cap assembly 14 is electrically isolated from the container 10 the peripheral cylindrical portion 34 also provides a resilient barrier between the cap assembly 14 and the container 10 thus the nonconductive seal 28 provides electrical isolation as well as a mechanical sealing of the cell the central cylindrical portion 30 includes a concentric cylindrical cavity into which is positioned a sleeve 36 the sleeve 36 is preferably metallic such that it may be compressed about the terminal 18 in the concentric cylindrical cavity of the nonconductive seal 28 the sleeve 36 is positioned such that a portion of the seal is located between the sleeve 36 and the.