In short, the gains are MINIMAL. Let's call it 5% longer life than leaving it plugged in. (we did the long discussion and came up with five percent.)
The problem of removing the battery is what happens when a Windows Update happens. You know the one where it warns about not turning off the PC? And without the battery the power could go out and it fails to boot. Seems like a false economy to remove the battery.
My laptop is almost always on a table or on my lap at home with an outlet always nearby. Since I almost always have the power cord plugged in, am I shortening the life of my battery by keeping the battery in? Should I remove the battery to prolong it's life? Or does this have no effect on the battery? Thank you.