Because of the cumulative effect, and using the Battery Power Scheme Defaults listed above:
•The backlight turns off after 3 seconds of no activity,
•The display turns off after 18 seconds of no activity (15 sec + 3 sec),
•And the device enters Suspend after 5 minutes and 18 seconds of no activity.
•If the User Idle timer is set to Never, the power scheme timers never place the device in User Idle, System Idle or Suspend modes.