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Mobile computing
5.375 x 8.375 ver 3.1
an extended period (more than a month), the battery may fail
to retain a charge. This may shorten the life of the battery, and
the battery light may not indicate a low-battery condition.
The computer also has an internal real-time-clock (RTC)
battery.
The RTC battery powers the RTC memory that stores your
system configuration settings and the current time and date
information. It maintains this information for up to a month
while the computer is turned off.
TECHNICAL NOTE: The RTC battery does not charge while the
computer is turned off, even if the AC adapter is attached.
The RTC battery charges when the computer is powered on.
The RTC battery may have become completely discharged
while your computer was shipped, resulting in the following
message during startup:
BAD RTC BATTERY
BADCHECKSUM (CMOS)
CHECK THE SYSTEM
This message may vary by model.
The RTC battery does not charge while the computer is turned off
even if the AC adapter is attached.
Monitoring battery power
The computer’s main battery light gives you an indication of
the main battery’s current charge:
❖ Blue indicates the AC adapter has fully charged the
battery.
❖ Amber indicates the AC adapter is charging the battery.
❖ Does not glow if the external power source is
disconnected or if the battery is completely discharged
