Abstract: A method for charging in a portable terminal is provided. The method includes charging a battery of an electronic device, using a natural resource, monitoring a charging state of the battery, and booting the electronic device based at least in part on the charging state and a determination that the electronic device is powered off.

Abstract: An apparatus and method for charging in a portable terminal are provided. The apparatus includes a controller and a charging management unit. The controller controls the charging management unit, absorbs a solar light, and charges the battery. The charging management unit senses a charging temperature of a battery cell when the portable terminal charges the battery while the portable terminal is powered off.

Abstract: An apparatus and method for charging in a portable terminal are provided. The apparatus includes a controller and a charging management unit. The controller controls the charging management unit, absorbs a solar light, and charges the battery. The charging management unit senses a charging temperature of a battery cell when the portable terminal charges the battery while the portable terminal is powered off.

Abstract: A power supply circuit and a power supply method using the same are provided. The power supply circuit includes a power interface to which power is supplied, a converter and a charging circuit connected to the power interface, a battery for receiving power from the charging circuit and for providing stored power to a system, the system for selectively receiving power from the battery or the system, a main switch disposed between the battery and the system for selectively interrupting the power of the battery to the system, and a control logic unit for switching the main switch according to presence of power supplied from the power interface.