A method of manufacturing an energy storage device for a medical device that includes creating an aperture in a case. The aperture includes an inner surface. The method also includes introducing an electrolyte into the case through the aperture and moving a sealing member into the aperture. The sealing member includes an outer surface. Furthermore, the method includes sealing the aperture only with the sealing member and creating a substantially hermetic seal between the inner surface of the aperture and the outer surface of the sealing member.
