Q: Battery life dropped considerably on Mountain Lion.

After refresh to Mountain Lion on mine macbook for I have found a strong reduction of the duration of the battery.

I also wanted to note that my MBA is running a lot hotter now. Even when it is sitting with the lid closed to charge.

Is it possible this is degrading the long-term performance of our batteries? What do people think, should I raise this as a problem for my particular MacBook Pro with Apple tech support, or wait for a more generic response?

So here's my dumb question:  Did Apple not see this problem with the battery during their own testing?

I have wondered how Apple could have released OS10.8 with such an issue for portable owners. My Late 08 MBP has a newer battery with 250 cycles on it that went from 3.5 hours per charge to 2.5 after installing Mountain Lion. Let's hope that Apple posts an update quickly.

Im also experiencing the same increased battery usage, thank god im not alone in this. I really hope Apple release an update to counter this, I keep thinking that its an incompatible app, but I have installed all the updates available.

alwaysforever wrote:

 

I guess this is something I should be concerned about, too.

 

I have a 2011 MBP, and I use wall power almost all of the time. Still, my battery doesn't seem to want to charge above 98%. I figured that was how it is supposed to be, so I didn't worry about it.

 

Then today, I went to set it up and the indicator light was green on my charger, so I turned it on. The battery was at 97%. This never used to happen with Snow Leopard. If my indicator was green, I was at 100%.

 

The reason you haven't seen it before is almost certainly that you haven't plugged in your laptop when it was at 97% charge before.  If your adapter shows a green light at 85%, I might worry that you have something wrong with your charge circuitry or, more likely, with the orange light on your power adapter, but a green light at 97% is perfectly normal.

To maximize battery life, most modern electronic devices(*) do not charge their batteries until they have reached a certain amount of discharge.  IIRC, a typical bottom limit is somewhere around 95% of its capacity.  Different versions of the OS may lie about what 100% means to hide that detail, but that's what's happening.  For example, IIRC, newer versions of iOS actually define their 100% mark such that it always shows a charging indicator when the number is less than 100%.  As a side effect of that definition, an iPad continues to charge for an hour or so after it shows 100%.  IIRC, most or all versions of OS X provide the actual percentages, so you see the opposite behavior, where the device won't bother to start charging if the battery is mostly charged.

(*) And then, you have UPSes.  I think they must trickle-charge their batteries constantly.  That's the only way I can explain batteries burning up after only two or three years of almost complete disuse.  Blech. 

Aside from the issue that since installing Mountain Lion, my late 2008 MBP 15" locks up about once per day or two, I did discover today that it's also killing the battery.   In standby, the battery died in an hour.    It used to last about three hours in use and for days in standby.

I'm very disappointed in Apple.   Never had anything like this happen before and I've been using Macs since the beginning: 1984.

Battery life of my MBP INCREASED after upgrade. Early 2011 13 inch MBP.

Cadaceus wrote:

 

...why there ACTUALLY WERE broken permissions after one day of installing/usage is a question for itself...

There aren't.  When "Repair Permissions" encounters multiple package receipts that describe the same file, and when those receipts have different opinions about what the permissions for that file should be, the repair process has no way to really know which one is right.  So it picks one.

Unfortunately, your permissions are probably wrong now, where they weren't really wrong before....  Fortunately, the resulting changes are almost always irrelevant.

Bottom line: unless you're regularly booting into Mac OS 9 on an older Mac, you probably don't need to run Repair Permissions.

Maybe I should demand a new battery from apple under my apple care. Is this frying the battery or impacting its FULL potential - likely

RenGR wrote:

 

That is an interesting suspicion! My MBA 13" (2011) does freeze in irregular intervals. Whenever it does so, there's at least mail.app running and occasionally mail.app shows weired graphics debris from another application running 'in behind it', e.g. Safari. To be sure, it froze under Lion too, battery life seemed 'normal', fans ran less often or not as speedily. So, it maybe that my MBA has faulty memory (as tech. supporter seemed to think)...

Yes, random freezes of the entire OS (as opposed to an occasional freezing single application) are almost always caused by bad RAM.

I too have some issues regarding battery useage. I have a fairly new MBP from late 11' and can only get about 4 hours out of it. It locks up randomly and when it's sleeping it drains quickly. 12 hours on sleep use up 12% of my battery. This all changed JUST when I upgraded. It also runs very hot.

Not a dumb question.

well, another interesting note for me is that when i boot camp into windows 7, the battery life also displays as only about 4 hours on a full charge.  this could be totally dependent on windows 7 settings though...

either way, i'm going to downgrade to lion tonight, on a fresh install, and hopefully that'll solve my woes.  if not, i guess i'm stuck carrying my brick around...

can anyone else boot camp into a different OS and report what battery life it shows?