an electric storage battery and method of manufacture thereof characterized by a feedthrough pin which is internally directly physically and electrically connected to an inner end of a positiv electrode substrate . a c - shaped mandrel extends around the pin and substrate end enabling the pin / mandrel to be used during the manufacturing process as an arbor to facilitate winding layers of a spiral jellyroll electrode assembly . the pin additionally extends from the battery case and in the final product constitutes one of the battery terminals with the battery case comprising the other terminal . active material is removed from both sides of the outer end of the negative electrode in the jellyroll to allow room for adhesive tape to secure the jellyroll . the electrolyte is injected through the open end of the case after the endcap is welded to the negative electrode but before sealing the endcap to the case . the electrolyte is preferably injected through the c - shaped mandrel to facilitate and speed filling .