Elongate battery for implantable medical device

A method of operatively coupling a medical device to a patient comprising:

• operatively coupling a lead of the medical device to cardiac tissue of the patient;
• implanting a control assembly and a battery assembly of the medical device within the patient, the battery assembly including a cathode, an anode, an electrolyte, a housing assembly encapsulating the cathode, the anode, and the electrolyte, and a first electrode exposed from and electrically insulated from the housing assembly, one of the anode and the cathode being electrically coupled to the first electrode and the other of the anode and the cathode being electrically coupled to the housing assembly, and one of the cathode and the anode being enclosed by the other of the cathode and the anode;
• supplying power from the battery assembly to the control assembly;
• and
• controlling electrical signal transmission through the lead.

A battery assembly for an implantable cardiac device that is implantable in a biological tissue comprising:

• a cylindrical cathode;
• a cylindrical anode;
• an electrolyte
• a substantially cylindrical housing assembly encapsulating the cathode, the anode, and the electrolyte;
• and
• a first electrode that is exposed from and electrically insulated from the housing assembly, one of the anode and the cathode being electrically coupled to the first electrode and the other of the anode and the cathode including an outer surface that abuts an inner surface of the housing assembly to be electrically coupled to the housing assembly, one of the cathode and the anode being enclosed by the other of the cathode and the anode.