MacBook Performance Dropping On AC Power

@ singularity - that's true of older batteries, but the current generation of Lithium ion batteries start to lose maximum charge the moment they come off the production line, I think the average loss in a year if left in a warm environment (like that of an operating laptop) is around 40% of it's potential capacity. If it's removed from the laptop when the laptop is plugged into mains the rate of decay is substantially reduced (enough to give you several more months of good usage) and even more so if the battery is kept in a cool place.

Are there really people out there who pull the battery out, so if they want to pick the laptop up and sit on the sofa for a bit they have to put the battery in first?! I suppose it takes all sorts, funny old world etc. etc.

@ Gnormie - you are perfectly right, however the high operating temperature (especially in overheating Apple notebooks) significantly reduces battery life over time (especially if your laptop is plugged in most of the time). The best practice to maximize battery life is nonetheless the same: to remove the battery and store it in a cool place. Besides, this – so called – feature has been put in place by Apple with older generation of laptops (and batteries) as well (as pointed out by other comments in this forum) so I thought it to be worthwhile mentioning.

@Ben – why don’t you read the very article you have mentioned to the end, with special attention to how to prolong battery life. But you get points for research...