Patent ID: 8406882

Claim:
An apparatus, comprising: a battery including a plurality of flat battery electrode layers disposed in a battery case, the battery case having a planar battery surface which has a battery interface perimeter; a capacitor including a plurality of flat capacitor electrode layers disposed in a capacitor case that is separate from the battery case, the capacitor case having a planar capacitor surface which has a capacitor interface perimeter; and a hermetically sealed implantable housing having a first shell and a lid mated to the first shell at a first opening, the first opening sized for passage of the battery and the capacitor, the implantable housing defining a housing interior, wherein the battery and the capacitor are disposed in the hermetically sealed implantable housing, and the capacitor is stacked with the battery such that the planar battery surface and the planar capacitor surface are adjacent, with the capacitor interface perimeter and the battery interface perimeter substantially coextensive, and wherein the battery and the capacitor define a power source form factor with an exterior contour including an exterior battery contour and an exterior capacitor contour, the exterior contour being continuous and substantially matching at least a portion of the housing interior, wherein at least one of the plurality of flat battery electrode layers has an outer battery perimeter that is smaller than the battery interface perimeter, with the exterior of the battery case contoured to curve from the outer battery perimeter toward the battery interface perimeter, and wherein at least one of the plurality of flat capacitor electrode layers has a outer capacitor perimeter that is smaller than the capacitor interface perimeter, with the exterior of the capacitor case contoured to curve from the outer capacitor perimeter toward the capacitor interface perimeter.