This restored my Mac Book to a usable state while using the battery -- battery lasted 3 hours instead of 45 minutes
1. Turn off the computer.
2. Hold down Ctrl+Option+shift
3. While holding down these button, press and hold the power button as well.
4. Hold all buttons for at least ten seconds.
5. power back on the computer.
Prior to doing this procedure, my fan was constantly on, and the computer was very very loud. After this stopped, and after a few days (I'm not sure why the benefit was not immediate) I noticed I was getting 2-4 hours of battery life again. Right away I noticed the fan wasn't constantly on.
Anyhow I know many are suffering from this computer ailment and I hope this helps. Hopefully Apple will have an update at some point so we can again get the coveted 7 hours or so of battery life.
I'm a very heavy macbook pro user I should mention, using Eclipse, instant messenger, terminal, textmate, Word, Excel, and everything else you can think of.
Thanks to this blog for showing me the way: http://blog.howardtang.com/2011/07/a-fixed-for-mac-os-x-lion-reduces-ba…
I copy the post in case his blog is down or he discontinues the site: but here's his linkback.