An access control system (100) for enabling functionality to a portable communications device includes a battery (120) for providing access to user-agnostic, system-agnostic and radio transceiver-agnostic control data to the portable communications device such as a portable two-way radio transceiver (110). A data connection (150) connected between the battery (120) and the portable two-way radio transceiver (110) provides control data to radio (110) and enables access to a predetermined set of device functions.