I'm writing this because I just upgraded to OS X Mavericks from Lion 10.7.6 and my battery life was significantly reduced. I'd upgraded once from Lion to Mountain Lion and encountered the same problem so I downgraded back to Lion.
Anyway, upgrading to Mavericks brought my battery from about 8 hours, a lot of times 9 hours after a full charge and surfing the web down to about 3.5 hours. Big reduction. THEN I tried these three things other people one this forum recommended:
1) I did the Reapir Disk Permissions thing on my hard drive through the Disk Utility App
2) I shut my computer down and did the PRAM reset: shut down then power up and press and hold option, command and the P and R keys before the gray screen appears and kept them held down until the computer restarted AGAIN.
3) Shut down computer again and pressed and held Shift, Control, Option and Power button down FOR MORE THAN 10 seconds. (I emphasize for more than 10 seconds because I'd tried it a couple times before for less than 10 seconds and it didn't seem to work).
Then when I turned on my computer the battery life showed about 6 hours which I hadn't seen since before the upgrade.
Now the percentage is at about 71% and reading about 5 hours remaining as I type this running Chrome.
Hope this helps some of ya'll. I'm greatful for those of you who took the time to list the steps you took to fixing the problem.
Godspeed.