Q: Battery life dropped considerably on Mountain Lion.

And another person who'x expiriencing the 5h (4h30min) instead of 8h problems...

I did noticed somthing strange though.

Using gfxCardStatus, so that I could run (the whole day) on the Integrated GPU only,
and using iStat (and others),

I noted that the GPU (my GT 650M) always was 5 to 10 ºC hotter then the CPU :O

So I think that the GPU still is on when using the integrated GPU...

Yesterday I verified disk permissions, repaired disk, etc all via the disk utility when turning on my macbook late 2011. I was very pleased to see that my battery had gone back to 8 hours plus. today i am dissapointed again as it has dropped considerably once more. I am currently at 55% and have 2 hours left.

Hope a fix comes soon.

Ditto, just adding my voice and hoping for a fix!

Just adding my voice, Apple needs to come out with a fix soon. My 5 month old macbook pro used to get a good 7-8 hours out of one charge and now I am down to 2 hr 30 min. I'm extreemly dissapointed and very worried for the overall health of my battery : (

Same im dealing w/ this bs 2!!! i took it to apple last week and the genius tells me im lying ... mad bs

Same **** here!!!
Battery life ist dow to only ca. 2 hours - new MBP (purchased on Monday) gets hot as ****...

Hi Viam,

I did a clean install of ML and had this battery issue. Since this is a work machine I did as you mention... Installed Lion clean from and dvd I had made and once complete clicked the software update and yes... There were several updates which I downloaded.  Hope this helps!

Kevin

Same here on a new MBP that i've only had for a week so far. It's getting to be really frustrating. I've got my screen brightness at a really low level and i'm not even doing anything intensive. I hope they fix it soon.

Hello Everybody,

I'm french, sorry for my english.

I have a macbook air 13" 2011, with same issue, after my clean install ML.

No soucy under Lion, good battery life, 7 hours

But with ML, i see a drop in battery life, and the left coner of the keyboard, warmer.

So I try this :

- reset PRAM / SMC > nothing

- Power Nap disabled > nothing

- disable Notification > YES

after disabling Notfication center, no more left corner warmer and a big boost in battery life.

here is the tuto : http://osxdaily.com/2012/08/06/disable-notification-center-remove-menu-bar-icon- os-x/

I also disabled the trackpad access

waiting for a really fix, you can try my solution.

Last thing, i wouldn't step back to lion, because performance of my HD3000 is incredible, try Diablo 3 and you will see. I have destroy my bootcamp, fps was the same in both system, ML and win7

Good progress and credit to Apple!

Was emailed and called today proactively from Apple Support as a result of this thread.

They are taking the problem seriously and spent a good 20 mins on the phone getting data from me.

They also have sent me the tool to collect the data from my machine and send it back to them and recognise many people are having this problem. Was advised to keep checking for software updates also.

So great news they reached out, acknowledged the issue and are working to resolve it.

Thanks Apple for great support. Looking forward to the resolution.

One more... hope to see Apple fix this soon!

Please ask the team involved in Snow Leopard, the last OSX without battery problems

Before Lion and Mountain Lion, my MBP last an overseas flight, now... he dead on departure! Thank Bezos for Kindle!

Yeah. I would think there must be something similar that makes it work. I am almost one week into the clean install method and I have seen great battery life. My overnight sleep drain is only about 4-5% and right now battery is at 37% and still shows 1:55 hours remaining with Dreamweaver, Safari, Mail, Twitter, Mint open.

It's definitely gotten better and seems stable for now.

My battery life used to be about 7hours before i installed. Now it starts at 5hours and sometimes under. I paid for this upgrade and Im starting to to think I'll go back to a windows laptop in my next purchase. This is not acceptable when we all pay so much for these products and so called apps.

Apple, sort youselves out before u loose ALOT of money and customers........

BTW, just tried jy-m's soloution (above) of turning off notification centre and it worked! Battery life just increased by 2 hours!

JY-M, your a genius!!! 

My new macbook with mountain lion preinstalled just arrived via Fedex today.  Do you think I should avoid turning it on until a fix is released, given the reports that the battery drain issue can wear down the battery and cause a loss of cycles/life?

Would this issue affected a new macbook out of the box?

Thanks everyone for your advice.