Abstract: An improved external controller useable with an implantable medical device is disclosed. The external controller comprises a front cover, a back cover, and a sub-assembly. The sub-assembly comprises an electronics chassis on which non-surface mount components, such as the telemetry coils and the battery, can be affixed. The sub-assembly also includes the printed circuit board for the external controller, which is integrated into the chassis and electrically coupled to the telemetry coils and the battery. Once completed, the sub-assembly can be bolted between a front cover and a back cover, such that edges of the sub-assembly comprise the edges of the external case of the external controller.