NOVELTY - The device (100) has a power management control unit that monitors an electric power accumulated in a power supply unit. A residual quantity of monitored electric power chosen is determined to be greater or less than a standard value. The power management control unit controls a LED to emit a light to a primary pattern and a secondary pattern when residual quantity of electric power chosen is greater than or lesser than standard value respectively. A power supply unit is provided with a battery e.g. a lithium ion (Li-ion) battery and lithium polymer (Li-Polymer) battery.    USE - Portable lighting device with LED.    ADVANTAGE - The portable lighting device is provided with the ability to effectively control the illumination and color temperature. The portable lighting device is featured with the high phosphor conversion efficiency and prolonged lifetime. The fuel price necessary for existing liquid fuel lamp and battery value necessary for battery exchange type lamp can be reduced and the maintenance is made more possible with the affordable price. The light emitting pattern is changed and the replacement time of the dry cell and charge time of the battery are given as notice to the user. The additional electricity does not inform the replacement time of the dry cell and charge time of the battery by the used separate lamp, so that the charged electric power can be efficiently used. The brightness is controlled by a three stage, so that the delicate dimming is made possible. The OFF contact point is placed in the position adjacent to the most dark brightness and the most bright brightness, so as to effectively control the brightness. The easy and convenience operation is provided to the user. The battery running time is remarkably improved and the calorific value and power consumption is significantly reduced, so that the luminous efficiency can be maximized.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) operation method of portable lighting device; and    (2) computer-readable storage medium storing program for operating portable lighting device.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic perspective view illustrating the outer structure of the portable lighting device.    Portable lighting device (100)    Handle (110)    Housing (120)    Light emitting unit (140)    Hanging arch (160)