Turning off battery while on AC

[Любомир Григоров]

Sorry if this has been answered, but is there a way to set a laptop (I have
ThinkPad X220) not to draw energy from the battery when it's on AC? In
Windows once the battery is not charging and you are on AC, the battery is
totally bypassed. You can imagine this being better than it constantly
charging and being used.

Is this something that is hardware built in, or is it controlled by the OS?
Is there an equivalent in FreeBSD? (or maybe GNU/Linux)?

Cheers.

-- 
Lyubomir Grigorov (bgalakazam)