Panasonic CF-W5MWEZZBM - Toughbook W5 - Core Duo 1.06 GHz Reference Manual page 19

Battery Power
We recommend that you become familiar with alarm settings to become aware when battery
power is low.
A. When making a setting for [When the alarm goes off, the computer will] in [Alarms] -
[Alarm Action]:
Add a check mark for [Force stand by or shutdown even if a program stops
responding].
B. Set the value for [Critical battery alarm] to 5% or more.
This is necessary for the standby or hibernation to be completed (assuring data is
saved) when the remaining battery power is low.
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