Battery life dropped considerably on Mountain Lion.

I tried the suggested methods of verifying the disk, repairing permissions, resetting PRAM and NVRAM... All of this gained me about a 25% improvement to remaining battery life.... Up to about 3 hours remaining.

Oddly enough, I went into system preferences >energy saver > restore defaults.

I'm now at 76% and showing 5:08 left..... Don't know if this will last but the results were immediate.

I'd be curious if this worked for anyone else.

yup, absolutely!! running back on lion now, and instead of 20 % in 30mins, i have been sitting on about 70% full charge for most of the day, under normal usage, prob been on it for about 2 hrs and it has only dropped aprox 5%. i completely believe that it is a mountain lion issue...

I noticed the same issues with the battery, CPU and GPU on my early 2011 MacBook13" core 2 dou. I also noticed that after a sleep-mode the W-LAN does not find any networks, i always have to deactivate and reactivate, to be able to connect with my network.

Has anyone seen anything remotely close to 7 or 8 hours after the ML upgrade?

I've been using the GM developer's release of ML since July 10th, on a late 2011 MBP, and am still getting 7+ hours on my battery. The problem just seems to occur on certain machines - there seems no consistency.

Clinton

Does this problem occur with clean installs of mountain Lion without any third party programs installed?

Has anyone who purchased a new computer with mountain lion pre-installed had the same issue out of the box?

Mine is a clean install and I'm having major batter issues.

Me too seeing a considerable drop in battery life since the upgrade.i was getting a solid 6hrs+ before the upgrade and now i get only 3-4hrs max.

Did an upgrade from Snow Leopard on my Macbook Pro 13" (2010).

Also, does powernap work for anyone? My wifi disconnects when the computer goes to sleep and therefore the is now way it can download mail, or calendar invites, etc.

Guys believe it or not.

Today I got a call from Apple. During this phone call, a guy said the engineers at Apple are investigating what is going on and he asked me if I could answer some questions. He inquired me about the kind of programs I regularly use, if I use iCloud, Dropbox and etc...

He also wanted to know what I do if I use the laptop for surfing the web, itunes, etc.

After theses questions, he sent me an app to capture data from my computer. I ran the program and sent the results back to him.

I must say I was extremely surprised to receive such call. I'm in Brazil and they saw one of my post here and they decided to call. Has anyone else receive such call?

That's why I'll always be a GREAT fan of Apple.

Power Nap only works with MBPs that have Apple-supplied flash storage. If you have such a machine, you should be able to get it to work. Do you have the Retina display?

Clinton

I got the call, too! I love Apple! I told the caller we're in this together; just want to improve the OS for everyone, if in fact there is an issue with it draining the battery.

Btw, do I need to upgrade the firmware for PowerNap to work?

I have a retina display mac. But the wifi disconnects when the computer goes to sleep. Is this supposed to happen?

Also, try running Safari in Private mode and see if that helps the battery issue. Private mode writes data to memory, instead of disk. I've noticed some battery improvements using private mode.

yes, Apple released a new firmware for the rMBP.