Compaq Armada 1500c - Notebook PC Reference Manual page 28

If two batteries are installed in the computer, battery charge
depletes beginning with the battery pack in the DualBay, then the
battery pack in the battery bay.
If two fully charged battery packs are installed, you can remove
one battery pack while the computer is on without affecting
system operation. With only one battery pack installed, turn off
the computer or initiate Hibernation before removing the battery.
When the computer is in Suspend, you must always have a power
source, either a fully charged battery pack or AC power, before
removing a battery pack.
See the Armada Quick Reference for details on using
battery packs.
Rechargeable battery packs can be used in the computer battery
bay or DualBay. To remove the battery pack from the battery bay
(if you are using one battery pack), turn off the computer or
connect to AC power, then pull down on the battery pack release
latch , and remove the battery pack .