One example includes a configurable power source system for an implantable device having a predetermined power requirement, the system comprising a housing for a battery and a capacitor, the housing including a distance D between a first internal face and a second internal face, the housing adapted to fit within dimensions of the implantable device, a plurality of batteries of different thicknesses, each battery adapted to fit within a perimeter of the housing, a plurality of capacitors of different thicknesses, each capacitor adapted to fit within the housing and adjacent the battery and a pick and place system adapted to assemble a selected battery from the plurality of batteries and a selected capacitor from the plurality of capacitors with the housing to form a configurable power source at least meeting the predetermined power requirement for the implantable device.