Texas Instruments 4000M - Manual (Page 79)

Battery Release
The Battery Release removes the battery from the notebook while the notebook
is docked to the portable CD-ROM docking system. To release the battery, pull
the battery release tab out.
Battery release
Note: If you have a charged battery in the Portable CD-ROM Docking
System you can remove the battery from the notebook and replace it with a
fully charged battery without powering off either the notebook or the Portable
CD-ROM Docking System.
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