Disclosed is a mobile terminal capable of converting an operational state of a controller thereof upon generation of a preset event and controlling an operational state of a particular terminal having a communication connection under control of the controller, and a control method thereof, the control method for controlling power functions within a vehicle telematics control unit comprising: accessing stored voltage information for a battery included in a vehicle; determining a present voltage characteristic of the battery based on measurements of voltage; determining whether a difference exists between the stored voltage information and the present voltage characteristic; converting an operational state of a vehicle telematics control unit responsive to determining that a difference exists; accessing threshold information associated with the battery; comparing the present voltage characteristic of the battery to the threshold information; determining whether the present voltage characteristic of the battery satisfies a threshold requirement indicated by the threshold information; and generating a first control signal responsive to determining that the present voltage characteristic of the battery satisfies the threshold requirement indicated by the threshold information.