MacBook Pro battery not charging properly? Apple may give you a free replacement
It's an unfortunate fact of life that over time all laptop batteries become less efficient. The machine that once got your through the day will eventually only last a couple of hours -- perhaps even less.
Age is one thing, but sometimes there can be a hardware or software problem that exacerbates the issue. And this is case for some MacBook Pro owners. But there's good news. Apple may replace your battery free of charge.