Standard Maintenance

For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month.

Got the info from here:-
http://www.apple.com/batteries/notebooks.html

Apple say Don't Plug in always. People say leave AC Plugged in.

This post has been edited by blizzzy: Sep 13 2009, 11:04 PM