Sony PCG-SR5K - Manual (Page 23)

Connecting a Power Source
To Insert the Battery Pack
You can insert or remove the battery pack without turning off the
computer when your computer is connected to the AC adapter. Before
inserting or removing a battery pack, close the cover.
1
Move the lock lever on the bottom of the computer to the UNLOCK
position.
2
Align the grooves and tabs on the battery with the tabs and notches
on the back of the computer, and then slide the battery toward the
computer until it clicks into place.
3
Slide the lock lever into the LOCK position to secure the battery on the
computer.
Lock lever
Grooves
Battery