An implantable cardioverter defibrillator ("ICD") comprises a battery, control circuitry and a capacitor assembly. The capacitor assembly includes at least one capacitor, a flex circuit for connection to the control circuitry of the ICD and a first and second support portions. The flex circuit is arranged between the first and second support portions and includes a plurality of tangs for connecting to the anode and cathode of the capacitor(s), as well as to the control circuitry of the ICD.