User selectable run-time for display device and method of reducing power consumption for display device

A method of operating a portable display device, comprising:

• powering an image display region by one of at least one power input port and a battery power supply;
• determining one of receipt of external power by the at least one power input port and current capacity of the battery power supply;
• and
• selecting a run-time period for displaying images within the image display region,
• wherein a user is provided with a display showing a maximum available run-time period based upon the determining one of receipt of external power and current capacity of the battery power supply.

A method of reducing power consumption of portable display device, comprising:

• powering an image display panel with a battery power supply;
• determining current capacity of the battery power supply;
• selecting a run-time period for displaying images within the image display region based upon the determined current capacity of the battery power supply;
• and
• displaying the selected run-time period within the image display panel.