Compaq Armada 7400 Reference Manual page 42

If your battery charge display seems to be inaccurate, you may
need to recalibrate your battery pack. Check the calibration status
of your battery by selecting Start Æ Settings Æ Control Panel Æ
Power Æ Battery Calibration tab. View the battery calibration
reports in the Status column.
A battery pack can only be calibrated if the Status column beside a
battery pack reports "Needs Calibration."
1. Connect the computer to an external power source.
2. Turn on the computer.
3. Insert the battery pack into the computer battery bay.
4. Select Start Æ Settings Æ Control Panel Æ Power Æ
Battery Calibration tab.
5. Select the battery pack you want to calibrate.
6. Select Start Calibration.
Shut down the computer.
or
1. Select Start Æ Settings Æ Control Panel Æ Power Æ Battery
Calibration tab.
2. Select the battery pack being calibrated.
3. Select Stop Calibration. This selection is only visible during
calibration.