Q: Battery life dropped considerably on Mountain Lion.

so, reading the last 3 pages,  early consensus on 10.8.2 is bad except for 1 post? I was going to do a fresh install and post results but now I'm wondering if 10.8.2 did not solve everyone's problems then was their hardware damaged, there was some speculation on this way back in this thread.

10.8.2 definitely has silenced my fans. But it seems to have done nothing to save my battery life.  I'm going to let it drain 100% then reset PRAM, SMC and repair permissions. I will try a clean install and not install any apps after that for at least 24 hours (which basically S*CKS).  If still no dice, I'm running over to the Apple Store, with the case number from when I spoke to a tech about this on the phone.  I will DEMAND a new computer if they can not fix it right there on the spot.  This is complete bull-you-know-what.  I'm furious.  I really thought 10.8.2 was going to fix it.  I'm FURIOUS.

Lol have fun with that, if you get what your demanding, then that just means the manager wants to get you out of his store so they can continue prepping for the iPhone 5 release. Don't be unrealistic, the policy is after 3 major manufacturer defects, then they will consider replacing the computer for you. Go in, try to act like a level headed consumer because no one needs to have your attitude.

I'm pis.sed too, but I know their policy and I'm going to politely ask for a fix or a battery replacement.

Anyways, I'm back after an SMC reset charging up right now.

(late 2010) MBA

I updated to 10.8.2 (no clean install), I saw in Apple store that there was an update (firmware or smc or sth like that) and I did it to.

Unfortunatelly, there is until now no increase in the battery life.

Before my first update to 10.8 I had more than 6.30 hrs, now it says less than 4.

Spotlight (mdworker32) is running, so I will wait until it indexes all my harddrive.

I will wait until one full charge, recharge hoping it may calibrate my battery and I will go to service.

VERY DISSAPOINTED !  

Btw, is there any user that has a late 2010 macbook air that show an increase in battery life ?

If yes please tell me if you did a clean install or what step you took ...

SUMMARY: At the risk of jinxing things I can report that I am actually seeing an improvement to the battery life (and health) since performing a clean install of 10.8.2. on my Late 2010 MacBook Air.  I wiped the SSD, downloaded a full version of ML10.8.2 and installed it from a USB created with Lion DiskMaker.

DETAILS:

History: My MBA came w/Lion and I could rely on it to last around 6 hours under normal use.  To be fair the advertised rate is 5 hours on a full charge.  I generally have WiFi on, BT off, 50% to 60% screen brightness and normally do some web surfing, mail, etc.  As expected, music and videos would drain the battery quicker.     I Installed ML July 25th and immediately experienced the severe battery drain others saw here.  It would drop about 1% per minute and would barely last 2.5 hours under the same load, usually less.  Installed 10.8.1 and gained about an hour so average was up to about 3.5 hours.  During this time the battery health dropped alarmingly from 95% @119 cycles to 93% at 125 cycles.

I ended up "downgrading" to a fresh install of Lion and did see a marginal increase in battery life, but not much.  The SMC was changed with the upgrade to ML and of course that didn't change with the Lion install.

Today after the fresh install of ML I charged it to 100%  Initially it looked like I had picked up another hour or so, so possibly up to 5 hours use, depending on what I was doing.

Right now everything is at the default settings and I've installed only two apps, Coconut Battery and Battery Health so I can measure any progress or lack thereof.  All I have open are Activity Monitor, Safari (inactive), Battery Health and Coconut Battery.  Since it's a new install Spotlight has been indexing for about 45 minutes, using 10% - 20% of the CPU.  Otherwise it's quiet.

As of now Battery Health shows that my battery is at 90% and that I have 5:37hrs at current usage (Battery Monitor matches). Like at least one other poster here I have seen some major swings...from 4 hours to over 8 hours, but it seems to settle down once I stop using it and is pretty stable otherwise.

There was one oddity during the installation.  After the initial ML install and ensuring that I was running 10.8.2 I checked Software Update and it listed "MacBook Air SMC Firmware Update 1.7" and "iTunes 10.7".  I decided to install Battery Health and Coconut Battery first so closed the Mac App Store and downloaded BH and CB.  I checked Software Update again and neither the SMC or iTunes updates were listed.  ???  I tried a couple of times again (both on battery and A/C) and still nothing.  I went to Apple's Support/download website and found the SMC update and installed it.  Checked Software Update after that and iTunes 10.7 was listed again.  Odd.

The other oddity is that my battery's health is now showing 96%...actually 1% higher than when I was running Lion.  I don't know if the accuracy has improved or if it's becoming less accurate.  Time will only tell.

BOTTOM LINE:

Although it doesn't look like I've gotten back to square one, after a fresh install of 10.8.2 I am actually seeing a marked improvement in battery life (and possibly health) over the original installation of Mountain Lion 10.8.  I'm still convinced this is a combination SMC/component issue, but it looks like Apple has addressed this to a great extent at least for my MacBook Air.  I plan on keeping it running for a few more hours, put it to sleep overnight (Power Nap is enabled) and see how it looks in the morning.

Spotlight indexing has finished now.  Here's a screen shot showing the various details:

If I were to show this to a Genius at an Apple store I think he or she would tell me that things look pretty normal.  Even though it's not as good as when I had Lion installed, it should deliver the originally promised battery life now.

I'll follow up tomorrow.  Best of luck to others...hope everyone's able to get things sorted out!

I've installed the latest update and the fan is still running even if the CPU is idle around 90 percent.

No improvement for my white 2009 macbook.

I' ve learned my lesson, I' ll wait with the IOS 6 update!

I upgraded to 10.8.2 and battery sucked less than 2 hours on a macbook air. Then I reset the SMC and voila, I'm back to 5 hours. Finally!

Currently downloading the 10.8.2, on rMBP.  Funny thing is, through software update it says it was only 307.8 MB.. very odd

Kenji, relax.  You do it your way and I'll do it mine.  I'll be nice.  I'll be courteous.  But I'm not monkeying around with BS "fixes" that I've already tried.  I patiently waited this long for 10.8.2 and so far it seems it will not work.  I DEPEND ON MY BATTERY.  I didn't Pay nearly $3,000 for a laptop to get $500 performance.  This is inexcusable...unless they're cool about it and make me whole.  If that means just a new battery, then fine.  But if the new battery performs like this one (only 9 months old--a late 2011 17" MBP,) then I will demand a new computer.  What other remedy would there be anyway?

Kenji said, "if you get what your demanding, then that just means the manager wants to get you out of his store so they can continue prepping for the iPhone 5 release...try to act like a level headed consumer because no one needs to have your attitude."

It's is your attitude, my friend, that no one needs, at least no one here in this thread.  We paid good money for these products and we should not be experiencing this kind of problem that has still NEVER been acknowledged by Apple.  To think otherwise is simply unimaginable to me.  Kenji, you must fall into one of two groups:

1) People who don't reply on their battery very often or for very long.

2) People who have money to burn.

I do not fall into either of those groups!  And I need my $3k investment to work.

downloaded so-called 'fix', restarted my computer...at 91%, i'm getting 3:37.  This is, sadly, an improvement from my 2.5hr battery life (my average for the past couple of weeks).  I opened up minibattery logger, and my batt health dropped 3% immediately after this install.  I'm keeping my genius bar appt. for tomorrow, this'll be my second time going in about this battery problem, so i should be, according to Kenji20022, one more visit (and some part replacement) away from getting a new mbp.  I'm uber disappointed though, i paid a lot of money for a machine that was supposed to be reliable for school, and instead, i'm trying to maneuver visits to the apple store into my schedule

Sounds like a deja vu repeat after 10.8.1. "Told you so" might not sound too sensitive.

It is software for some. Hardware for others. This is common sense.

dans... your expectations are off. You called it a $ 3000 "investment"... I lost too. markets so on...  If you invest be ready for risk. If not, never call it such. Only bonds are guarenteed... And if you are a frequent Apple purchaser, stats say you will get a lemon. If Apple decided my second MBA was a lemon (first one irrepairable trackpad), this one the drain.. it just happends. Two lemons in a row. It's called a lemonade. To believe other wise is missing a bit on this tech reality.

There is no point in getting mad- be it human nature. But whomever bought a pricy item and never had an issue (car, tv, computer, macbook)- let them throw a first stone at Apple. Go at the Genius bar, watch for 30 minutes people coming with issue units, and leaving. they have a problem hence being there. No one will convince them that their machine is infallible.

10.8.2 will work for some. And  not for others. Apple admits some of their machines do not work. As for the battery problem they have no reason to admit. It is not large enough to bug them.

Apple store visits can be a burden for some. Drop your 17" MBP at Apple in the morning, let them observe the huge drain - and they will run tests btw all day, not your standard plug in genius bar test. And if it does not last they will call it defective and replace it. If one does not choose th easy way out, problem is not with Apple.

Older macbook users- am not surprised it does not work.

New macbooks- if still not working, then easy option. Am downloading myself 10.8.2 prior to shipping back this MBA and see if it does make a difference. It is good to hear some users are experiencing resolution. Come back after 1-2 cycles let us know. And calculate the time- not whats shown but what you actually get. Surf 30 min, check again, and extrapolate, thats the real figure. if solved, great.

Waited and updated to 10.8.2

NO improvement. Battery draining as fast as before.

THIS IS CRAP !! Laptop that is usable only tethered...

I enjoyed perfectly good Macbook Air with really good battery life with no complaints until I made the stupid decision to upgrade to Mountain Lion.

I am really really disappointed in Apple. There are MANY of us who suffers and they do not give a rat's ***.

I think I could already call this arrogance.

I even have Apple care and to no avail "your MPA works just fine".... Great to know but why is then the battery capacity 40% what is used to be...

I give up and lesson learned. NEVER upgrade until 6 months or more has passed to see what happens.

PS.

Do not update to iOS6. Lessen learned from Mountain Lion. Upgraded my old spare iPhone and the satellite photos (at least for my area) are from Jurassic park period (no offence ment for creationists). That was the first bug I discovered...

@hop1967

what MBA do you have… year, etc?

Well, I installed the 10.8.2 combo update to my Mid 2009 MBP. My first quick experience is showing that it's quite an improvement. I was at 93% battery and was showing about 5:30 hours on battery. I don't remember it showing anything over 4, let alone 5, so as of now, I'm going to say 10.8.2 has made a big difference.

The next test will be to see what it shows when I wake it up in the morning - to see how much, if any, it drains while asleep.

I did a fresh install of 10.8.2 with a SMC reset and my battery life is finally back to normal!