HP Compaq Presario,Presario 800AP Supplementary Manual page 29

Warning
Your Notebook contains a
lithium-ion battery pack.
Improper handling of the
battery pack can result in fire
and chemical burns. Do not
disassemble, crush, puncture,
short external contacts, dispose
of in water or fire, or expose it
to temperatures higher than
140 °F (60 °C). Replace only
with the Compaq battery pack
specified for your Notebook.
See also
"Components on Underside"
in Chapter 2 of this guide for
help in locating the Battery
Stopper and Battery
Release Switch.
See also
"Caring for Your Battery"
later in this guide.
To connect the battery to your Notebook, place your Notebook
upside down and position the battery so that the side with the
label is turned down. Unlock the Battery Stopper first. Connect
the battery to your Notebook until it snaps into place. Then lock
the Battery Stopper.
To remove the battery, complete the following steps:
1. Save your files.
2. If the AC adapter is not connected, turn off your Notebook.
3. Unlock the Battery Stopper.
4. Slide and hold the Battery Release Switch on the underside
of your Notebook to the back.
5. Pull the battery out.