Provided is a method and apparatus for managing the power of a portable
computer system, in which a convenient user interface is provided. The
method includes calculating a range of a desired time-of-use based on
power consumption of the portable computer system and a remaining battery
capacity at a minimum power level of the portable computer system,
providing the calculated range of the desired time-of-use and a desired
time input box that allows a user to input the desired time-of-use,
inputting the desired time-of-use through the desired time input box, and
resetting the power level of the portable computer system according to
the input desired time-of-use.