My MacBook Pro went from around 7 hours of battery life to about 2 hours upon installing Lion. I tried everything that you can think of to correct the issue including reformatting the HD and doing a clean install of Lion. Apple engineers couldn't figure it out either. Apple even gave me a new battery, and the issue still persisted. In the end, it turns out that Carbonite's software that supposedly updated to run on Lion was using about 75-80% of my CPU. It was draining my battery. I deleted the Carbonite app and my battery life is back. I know that others have been having issues similar. Hope this helps. It was a pain trying to trace it down, but I got a free battery for my MBP out of it.