A portable terminal assembly comprises an enclosure having a distal end wall and a proximal end wall connected to a pair of sidewalls such that the enclosure walls connect a bottom surface to a top surface having a user interface to define an enclosure interior. The enclosure has a power source compartment positioned in the enclosure interior. The cover couples to the compartment situated in an opening in the bottom surface. The cover housing of the cover includes a cover surface, a pair of cover sidewalls, a proximal cover end wall and a distal cover end wall such that the cover walls extend from the cover surface to define the cover interior. A magnet is coupled to the cover interior, such that the magnet has a sufficient magnetic field strength for affecting the state of the contacts of a switch. The switch is mounted in the interior of the enclosure, such that the switch is coupled to at least one component receiving power from the power source when positioned in the compartment. It is recognized that the proximity of the magnet to the switch affects the state of the contacts and therefore the supply of power to the at least one component.