Q: Battery life dropped considerably on Mountain Lion.

This is 13-inch, Mid 2011 (4GB RAM)

Well I've down loaded and installed 10.8.2 Cfull combo with my MacBook Air 11" fully charged.

Reset SMC then Reset PRAM just to make sure and it would appear that there is some improvement but not much.

I still have por battery health although it's gone up a little I think 95% after only 29 cycles is not very good.

At the moment I am downloading iPhoto update Have Safari running and brightness on full. Running on battery I have seen 9% loss in just a few minutes and it's telling me 2:15 left @90% and to me that's just not good enough.

Mind you the MacBook AIr 11" is advertised at 4 hours so maybe I am expecting too much at full bright, Safari running along with an update downloading on Wi Fi

Then again while typing  this on my iMac battery has dropped another 2 % down to 88% but now the update download has finshed time left has increased to 2:35 so a 15 minute use gain with on app and download finished.

I haven't checked if there is a firmware update fir this thing yet software update doesn't tell me there is ?

Going to have to monitor this really still seems out of whack to me. Going to watch it over night 

@hop1967

thanks… was wanting to check what people use when they upgraded to 10.8.2… have been holding off on moving up from 10.7.5 until I here from others with the MBA mid 2012 13"

@schowave

what MB are you using?

it would be good if folks could put the basic info as to what MB they are using when they upgrade to 10.8.2… 11" or 13" MBA… 13" or 15" MBP… and the year/model

Guys,..  do not want to be prematurely glad... but... it seems something HAS changed to better way.

Here my history.

1. MBP mid of 2010.

2. OS X 10.8.1 installed over 10.8.0

3. Battery last 2 hours maximum, battery health is 82%, 607 cycles.

4. 1% has been drained per 1 minute.

I've installed 10.8.2

Things became worser. It showed me 1.5 hour for 100% charged battery.

I've installed 10.8.2 combo. Nothing changed again.

I've reset my PRAM and SCM (http://thenextweb.com/lifehacks/2010/12/04/how-when-why-to-reset-the-pram-smc-on -your-mac/) - and... here it is! For 50% charged battery it shows me 2 hours, i.e. for 100% it should show 3.5-4 hours (what I actually had for Lion!)

Keep testing...

I'm using a

15 inch MBP Early 2011

2,3 GHz Intel Core i7 (Quadcore)

8 GB 1333 MHz DDR3

Intel HD 3000 + Radeon HD 6750M + Hi-Res Display upgrade

OS X 10.8.2 (12C54)

This was my procedure:

when ML came out, i directly updated from Lion and the battery life was very bad! This is why i switched back to Lion, but battery didn't make much difference. Then I installed Snow Leopard and the battery life was excellent. So I stayed with SL until battery problems should be fixed. So yesterday, I did a clean install of ML and a SMC reset and the battery is as good as in SL. (Now showing 4:04 with 56% left, which is fine for me!)

Hope all of you will find a solution to that!

I reset the SMC and still no luck. 100% charge, and it shows 5 hours remaining. This wasn't a problem for me before 10.8.2, but now it's impossible to not notice the difference in battery life. This is the second time I charged my computer in the past 12 hours, and I barely used it. I have a mid2012 Macbook Air, and my wife has a mid2012 macbook pro. Her battery life dropped too, and gets just over 6 hours on a full charge.

10.8.2 installed. Again a horrible battery life.

The Update to 10.8.2 on my MBA 2012 13'' didn't change the battery life directly, but I can also confirm that things got better after I did a PRAM and SMC reset afterwards. I am now charged at 31% with an estimated battery time of 2:33 left. Im currently idle, just posting here with Chrome, Dropbox, Sparrow and Droplr in the background.

My first observation for 10.8.2. is that ML became faster. It was fast anyway. But it is lightning faster after the update. Apps open or close faster, boot time, etc. Internet substantially sped up- page rendition, graphics- even though my actual broadband is identical.

In actual usage battery drain appears gone. I still had it just before the update.  Essentially was plugging the unit every second evening. From -1000 mAh the MBA is now draining -600 to -800. Battery health reports  -5.96 watts, a discrepency, so I noted right away it is no longer synced with actual consumption. Equally, after the reboot, Watts and Battery health had not loaded on startup. Interesting...

Sill have to do the standby test, 10 hr sleep/drain and will report my findings here.

ciao giulio,

sorry for the late reply.

i still have 10.8.1 and as said suddenly it became amazingly performing.. i didn't upgrade to 10.8.2 yet.

honestly i'm a a little bit afraid to do it.. as for the ios 6, as i have an iphone 4s. i would not have any issue like these...

hello salty,

as said i honestly don't know what's happened.

as said, i did a backup with time machine, then i tried to do a clean install of ML with one partition as adviced me from the guy at the genius bar. it didn't alowed me giving me an error. so i give up waiting the week end after to go at the genius bar and ask what to do. but suddenly, the battery performed as you can see above..

sorry that i cannot be more precise, but i really didn't do anything specific...

I absolutelly agree with Beisarius that ML became faster and a very stable system on my late 2010 13" MBA.

Actually yesterday I was very dissapointed with the update to 10.8.2 from 10.6.8.

I had also installed the new firmware, did a SMC reset.

Today I was about to go to the service and I decided to do a clean install. Not having a cd or usb drive with 8gb to make a bootable installation, I holded ALT during restart and the 10.8 recovery disk appeared. I erased my 1st partition, downloaded ML from network (almost 2hrs!) but after then I can say the battery seem better.

At 99% battery (my baterry life is 91% after 159 cycles in 9 months) showed 4.30 hrs.

Now after some video for 1hrs and some surfing (after 2hrs) I am with 55% and 3:38 remaining. it seems maybe that the battery is callibrating or sth.

I cross my fingers and will come back later!

I still believe ML 10.8 killed some 6-7% of my battery in 2 days and I dont know how I can have it replaced.

Do 159 cycles in 9months when I ALWAYS FULLY charge and discharge for this system justify a 9% drop as cocunutbattery reports ? I dont know! I guess not. BUT I have to say that the system is really stable. this is the OS I love ! Not slow at all, for a laptop designed 2 years ago.

Hi, I've upgraded to 10.8.2 my MBA 2011 13", and now my battery do 5:30 hr, so nice. This with bluetooth connected with apple mouse, wifi and LCD to 1/3. As I do with Lion.

Good job

(I've reset SMC and PRAM)

To everyone:

- checking right away for battery performance is not the best time. Spotlight needs to index lots of changes. then the new updated firmware- for those that got it- will take time to sync actual consumption, also need to do a full calibration. So it would take 2-3 cycles of 10.8.2 to determine where is it at. We also do not want a false impression that it does work and then it begins acting up again. But, as I wrote, initialy impression is lightning fast and steady consumption.

To chris_gr: Full charge and discharge shortnes battery health. You are welcome to verify that with Li Ion tech description, or the battery university. Li Ion is meant to be partial/rapid charged  and only fully discharged/charged for calibration purposes. In other words, you reach 5-10 percent, PLUG for a while. if you  see green light, UNPLUG. Exactly as an iphone. Why do iphones last so much in health? because none of us actually wait till 2-3 percent (or black screen) before charging as we risk loosing a conversation. So we always charge bits here or there, especially if leaving the house and it is at 10%.

Same principle about macbook batteries. Always rapid charge and never let it fully discharge. Geniuses and Apple will tell you the same. So your overall loss of health makes sense, as did the ML drops, which drained the battery so fast it dinged its health.

Oh please, you spent money on something that is known to possibly have a problem from time to time. Your "3000$" Macbook is made from the same parts, and has the same quality control as my 1499$ Macbook Pro 13in. You might have better specfications but I find it astounding that you feel like you don't have a **** attitude by saying this.

"I will DEMAND a new computer if they can not fix it right there on the spot."

They can't fix it on the spot, they're busy with their store. They'll do for you what they offered me, a battery replacement and to come pick it up in 3-5 hours. I very much bought my laptop with money that I saved up from working because I'm a college student who's halfway there, and doesn't **** out money like some people who think 3000$ isn't a lot to throw around. And like Beisarius said, these aren't stocks, this is hardware that can fail jump back into reality bud.

And I'm a computer programmer, I rely on my computer for quite a bit. I have all my coding done in Xcode and if my computer dies in the middle of a project that I need to finish then guess what that means? I rely on a battery just as much as everyone else, your "business" or whatever you're going to pull out isn't more of a priority than anyone else's time and use of their laptop. You're not above the other Apple customers, and you still have to abide by the policy of 3 repairs, and then you'll be considered for a replacement. People like you getting handouts drive prices up for everyone in the long run, cause it's not just you doing this. It's quite a large amount of people expecting to complain to a manager and get what they want instantly. So get in line, and go through the process like everyone else, no one needs YOUR attitude, I'm just putting you in your place for being so arrogant.

Update: No improvement after a PRAM and an SMC reset, right now it says 81% on 3:30 but it's fluctuating a lot so I'm waiting for that to settle. Again just browsing like the last pictures.