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Mobile Computing
Charging batteries
5.375 x 8.375 ver 2.3
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 the following
error message during startup:
BAD RTC BATTERY
BAD CHECKSUM (CMOS)
CHECK SYSTEM
The above error message may vary by computer model.
The RTC battery does not charge while the computer is
turned off even when the AC adapter is charging the
computer. The RTC battery charges when the computer is
powered on.
If the RTC battery is low, the real-time clock and calendar
may display the incorrect time and date, or stop working.
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.
NOTE
NOTE