A method for constructing a battery that includes a can, a jelly roll contained in the can, a top insulator contained in the can adjacent to and above the jelly roll, and a battery cap. The method includes forming the can, forming the jelly roll, inserting the jelly roll into the can, inserting a top insulator into the can adjacent to and above the jelly roll, assembling the battery cap, including an outer conductive ring, an insulator ring, a conductive top plate, a conductive rupture plate, connecting a cathode to the conductive rupture plate, inserting the battery cap into the can, and welding the battery cap to an inner surface of the can.