88 Mobile Computing
Charging batteries
TECHNICAL NOTE: The recharging of the battery may not occur when
your computer is using all of the power provided by the AC adaptor to
run applications, features, and devices. Your computer's Power Options
utility can be used to select a power level setting that reduces the power
required for system operation and will allow the battery to recharge.
The battery may not start charging immediately under the following
conditions:
❖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
periodically operate your computer on battery power until the battery
discharges completely.
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 78
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 system, the RTC battery may only charge while
the computer is turned on.
NOTE