120 Mobile Computing
Charging the batteries
5.375 x 8.375 ver 3.1
computer off. It takes much longer to charge the battery while
the computer is on.
TECHNICAL NOTE: The battery does not charge while the
computer is consuming full power.
The battery may not start charging immediately if:
❖The battery is extremely hot or cold.
To ensure that the battery charges to its full capacity, wait
until it reaches room temperature (50 to 80 degrees
Fahrenheit, 10 to 26 degrees Celsius).
❖The battery is almost completely discharged.
Leave the power connected, and the battery should begin
charging after a few minutes.
HINT: Once the battery is fully charged, we recommend that
you operate your computer on battery power until the battery
discharges completely. Doing this extends battery life and
helps ensure accurate monitoring of battery capacity.
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