Keep in mind if you plug it in to charge and the battery is not lower than 95% it will not charge. This is to keep it from overworking the battery, extending it's life. That used to get to me when I got my first macbook but now I am glad that it works that way. If you want to see it get to 100% make sure it is below 95% and then charge it. I used to do this all the time. Now, never, unless I am heading out and I won't every last drop of juice in the battery.
But like Europa I never unplug it unless I am taking it with me. Of course mine is going with me quite a bit--even if around the house or out to the patio.
Michael