Panasonic CF-29 Series Reference Manual page 52

Battery Power
In the standby mode, do not remove/change the battery pack. Removing the pack in
the standby mode will erase your data and may damage the computer.
1
Power off your computer.
(⇒Operating Instructions "Starting Up/Shutting Down")
Do not shut down using the standby function.
2
Remove the battery pack.
1
Unlock the cover by sliding the latch (A) to the right.
2
Slide the latch down, and then without releasing it, open the cover (B).
3
Pull the tab (C) on the battery pack and remove it from the computer.
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