Compaq Armada 7400 Reference Manual page 41

If the battery pack has not been used for two weeks or more, fully
charge the battery before using your computer.
To charge the battery pack in the computer, connect the computer
to an external power source (optional Automobile/Aircraft
Adapter, external AC Adapter, ArmadaStation, Armada
MiniStationE/EX, or battery charger).
The battery power light turns on when the battery pack is
charging.
Charging may not occur immediately if:
The battery pack temperature is outside the normal operating
range of 50°F to 104°F (10°C to 40°C).
The battery pack is below normal discharge levels, which can
occur when a battery pack is not used for 2 weeks or more.
When the battery reaches the normal temperature and charge level,
it begins to charge until it is fully charged.
A fully discharged battery pack charges in approximately 3 hours
when the computer is turned off. When the computer is turned on,
charge time depends on the amount of power being used by the
computer.
The built-in battery gauge displays the amount of charge
remaining and is precalibrated for accuracy (To access the battery
gauge press
and to maximize battery operating time:
Fully charge and discharge the battery pack completely several
times prior to the first time that you use it.
Allow the battery pack to completely charge before removing
external power from the computer, optional ArmadaStation,
Armada MiniStation E/EX, or battery charger.
Recharge the battery pack before using it if the battery has
been out of the computer for two weeks or more.
Allow the battery to completely discharge to the low battery
condition through normal use.
). To ensure continued battery gauge accuracy