Charging A Battery Pack - HP Compaq 800c Hardware Manual

Charging a Battery Pack

All battery packs inserted into the notebook charge whenever the
notebook is connected to external power. External power can be
supplied through an AC Adapter or an optional Automobile
Power Adapter/Charger.
✎
An optional Aircraft Power Adapter can be used to run the
notebook, but cannot be used to charge a battery pack.
Battery packs charge whether or not the notebook is in use, but
charge faster when the notebook is off. Charging may be delayed
if a battery pack is new, has not been used for 2 weeks or more, or
is much warmer or cooler than room temperature.
While a battery pack is charging, the battery light on the notebook
is on. The light turns off when all battery packs in the system are
fully charged.
Identifying the battery light
Hardware Guide
Battery Packs
3–5