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Mobile Computing
Monitoring main battery power
Please make a complete back up of your data to external media
before discharging the battery. For more information, see “Backing
up your work” on page 74.

Charging the RTC battery

Your computer has an internal real-time clock (RTC) battery. The
RTC battery powers the System Time Clock and BIOS memory
used to store your computer’s configuration settings. When fully
charged, it maintains this information for up to a month when the
computer is powered off.
The RTC battery may have become completely discharged while
your computer was shipped, resulting in a CMOS error message
during startup. The error message may vary by computer model.
Depending on your computer model, the RTC battery may only
charge while the computer is turned on.
To recharge the RTC battery, plug the computer into a live electrical
outlet and leave the computer powered on for 24 hours.
It is seldom necessary to charge the RTC battery because it charges
while the computer is on. If the RTC battery is low, the real-time
clock and calendar may display the incorrect time and date or stop
working.
When Hibernation mode is enabled and the RTC battery is
completely discharged, a warning prompts you to reset the real-time
clock.
The computer can be used while the RTC battery is being charged,
although the charging status of the RTC battery cannot be
monitored.
Monitoring main battery power
The computer’s main battery light gives you an indication of the
main battery’s current charge.
❖Glows amber while the main battery is being charged
(AC adaptor connected)
❖Glows white when the main battery is fully charged
NOTE
NOTE