Implantable medical device battery

A battery comprises a tubular housing. An external surface of the tubular housing comprises a biocompatible material. The battery further comprises a battery header secured to an open end of the tubular housing, and the tubular housing and the battery header combine to form a substantially sealed enclosure. The battery also comprises one or more voltaic cells within the substantially sealed enclosure, and a feedthrough electrically connected to the voltaic cells and extending through the battery header to form a battery terminal. The battery header includes a radial groove opposite the tubular housing, and the radial groove is configured to receive a mating snap-fit electronic component subassembly of an implantable medical device.