Abstract: An exemplary method for conserving power of a portable communication device includes: supplying voltage by a power supply; distributing voltages to other units of the portable communication device including a communication unit and a backlight unit; the portable communication device entering a normal mode after being powered by one of the voltages; generating digital voltage signals corresponding to the voltage supplied by the power supply; detecting a voltage of the digital voltage signals to obtain a detected voltage; comparing the detected voltage with a predetermined value; and if the detected voltage is equal to or less than the predetermined value, changing from the normal mode to a power conserving mode, and stopping distribution of the voltages to at least one of the communication unit and the backlight unit. Thereby, an operational time of other units of the portable communication device can be prolonged.

Abstract: An exemplary method for conserving power of a portable communication device includes supplying voltage by a power supply of the portable communication device; distributing one or more corresponding voltages to other components; the portable communication device entering a normal mode and enabling user-selected prompts after being powered by one of said voltages; generating digital voltage signals corresponding to the voltage supplied by the power supply; detecting a voltage of the digital voltage signals to obtain a detected voltage; comparing the detected voltage with a predetermined value; changing a current mode of the portable communication device from the normal mode to a power conserving mode, if the detected voltage is equal to or less than the predetermined value and the current mode is the normal mode; and disabling a pickup button of the portable communication device. Thereby, an operational time of other units of the portable communication device can be prolonged.