An implantable pump system including an external driver. The implantable pump is driven by the external driver during normal operation but may also operate on a battery. The external driver is used to drive the pump with the mechanical energy of the impeller also being used to charge the battery. The external driver is also useful during emergency situations to directly drive the pump if the battery or internal coils should fail. The pump is also preferably implanted in a subpectoral location outside the patient's rib cage.