A power module assembly for being mounted to headgear is provided. The power module assembly can include a housing member and a cover member configured to mount thereto. The housing member and cover member can have a generally curved profile configured for fitting against a user's head. The housing member can be generally rigid, and the cover member generally flexible and resilient, so that the cover member can mount to the housing member with a snap fit connection therebetween. The housing member can further include a plurality of handles, so that straps of the headgear can extend through openings between the handles corresponding surfaces of the housing member to secure the power module assemble to the headgear.