Abstract: When a battery pack, comprising an overcurrent protection section for stopping, when a current greater than a first threshold value passes, a current supply, is connected to a power supply terminal of an information processing apparatus, the information processing apparatus draws a current greater than the first threshold value. Thereafter, an output current and output voltage of the battery pack are detected, thereby measuring a time period from when a current drawing section draws the current greater than the first threshold value to when the battery pack stops the current supply. When the measured time period is within a first predetermined time range, the battery pack is permitted to supply an electric power. On the other hand, when the measured time period is not in the first predetermined time range, the battery pack is prohibited from supplying the electric power.

Abstract: When a battery pack, comprising an overcurrent protection section for stopping, when a current greater than a first threshold value passes, a current supply, is connected to a power supply terminal of an information processing apparatus, the information processing apparatus draws a current greater than the first threshold value. Thereafter, an output current and output voltage of the battery pack are detected, thereby measuring a time period from when a current drawing section draws the current greater than the first threshold value to when the battery pack stops the current supply. When the measured time period is within a first predetermined time range, the battery pack is permitted to supply an electric power. On the other hand, when the measured time period is not in the first predetermined time range, the battery pack is prohibited from supplying the electric power.

Abstract: When a first group of contacts 31a is selected by a power switch 30, all power supply is stopped, when a second group of contacts 31b is selected, power from a power supply portion 27 is supplied only to an information processing circuit 20 and an LCD drive circuit 24, and when a third group of contacts 31c is selected, power from a power supply portion 27 is supplied to all of the information processing circuit 20, the LCD drive circuit 24 and a backlight emitter 26. Thus, an user can arbitrarily choose between turning on a backlight to obtain a bright and legible screen or seeing the screen through natural reflection light with turning off the backlight.