A medical device includes a case and a core assembly. The core assembly includes operational circuitry enclosed within a core assembly housing. The medical device also includes a battery assembly, which includes a battery enclosed within a battery housing. The case includes the core assembly housing and the battery housing. A first electrode is coupled to, and electrically isolated from, the case; and a second electrode is electrically coupled to the case. The second electrode is electrically coupled to the operational circuitry via a sensing pathway that includes a portion of the case. The battery is electrically coupled to the operational circuitry via an energy supply pathway that includes the portion of the case.