118 Mobile Computing
Charging batteries
5.375 x 8.375 ver 2.4.0
charge the battery with the computer off. It takes much longer
to charge the battery while the computer is on.
TECHNICAL NOTE: The battery may take longer to charge with
many applications open at the same time.
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 a 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
The computer contains an internal battery that provides
power for the real-time clock (RTC) and calendar.
During normal use, the main battery keeps the RTC battery
adequately charged. Occasionally, the RTC battery may lose
its charge completely, especially if you have had the
computer turned off for a long time.
If the RTC battery is low, the real-time clock and calendar
may display the incorrect time and date, or stop working.