Your laptop is designed for you to leave the battery in ALL the time. The circuitry inside the machine, the power supply, even the battery itself. It should be left in whether you've got it plugged in to a power conditioner or not.
And you should know that the battery acts as a power conditioner itself - all the power from the power supply goes through the battery, if it's in place.
Actually, a power conditioner, or UPS, is nothing more than a big battery with an alarm on it.
So. leave the battery in. Discharge it all the way once a month (pull the plug a few hours before you have to go to bed, let it completely die and then plug it back in). And use the computer manufacturer's recommended conditioning software every so often to keep your battery fresh.
As to whether a battery will discharge over time if not in the machine, yes, it will. Left for months or years, it will discharge. So, it's a good idea to bicycle your batteries if you have more than one, rotating them every few weeks.
Finally, it's fine to keep your laptop on all the time. I do, and my screen is fine. If you're using a plasma screen for a second screen, make sure your screen saver kicks in there, or you may burn the desktop pattern into your big screen.
Thanks for asking!
Herfra:
http://www.thedavidlawrenceshow.com/should_i_leave_my_battery_in_my_laptop_all_the_time_006696.html
Men som han selv skriver, så får du 5 forskellige svar fra 5 forskellige mennesker.
Men jeg syntes det han skriver giver god mening.
Nemlig at:
Strømmen fra strømforsyningen går gennem batteriet, hvis batteriet er inde i maskinen.Faktisk er strømforsyningen et slags batteri med en slags "alarm" i.
Lad batteriet blive i maskinen og aflad det ca. 1 gang om måneden.
Batteriet får forkortet levetiden selvom du ikke har det liggende inde i maskinen.
Men igen kommer det an på hvilken producent der har fremstillet batteriet.
Tag batteriet ud og se hvem der har lavet det. Gå ind på deres hjemmeside og læs vejledningen. (Det er meget sjældent producenten af computeren der har fremstillet batteriet selv, ligesom alt andet i somputeren.).