Power
Hardware and Software Guide
2–17
Battery Packs
When the notebook is connected to external AC power, the
notebook runs on AC power. When a charged battery pack is in
the notebook and the notebook is not connected to external
power, the notebook runs on battery power.
The notebook switches between AC power and battery power
according to the availability of an external AC power source. For
example, if the notebook contains a charged battery pack and is
running on external AC power supplied through the AC adapter,
the notebook switches to battery power if the AC adapter is
disconnected from the notebook.
You can leave a battery pack in the notebook or in storage,
depending on how you work. Keeping a battery pack in the
notebook enables the battery pack to charge whenever the
notebook is connected to external AC power and also protects
your work in case of a power outage.
On the other hand, battery packs in the notebook slowly discharge
when the notebook is turned off. For this reason, the primary
battery pack is not shipped inside the notebook and must be
inserted before the notebook can run on battery power.