Battery and AC

[alsohere]

Should I run the laptop without the battery if on ac power?
Or will doing such damage components inside the t400?

[EOMtp]

The answer to both questions is "No!" ... Although the machine will run with only the AC adapter, there is no reason whatsoever to remove the battery while on AC. The charging circuits in Thinkpads are "intelligent", i.e., they do not damage batteries by "pumping" them continuously ... + using a battery provides redundancy which prevents loss of data and/or corruption of files in case of loss of AC power.