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Hyper7Death Level 1 Level 1 (0 points)

I recieved this MacBook Air yesterday and performed a full charge cycle to calibrate the battery's microprocessor, but I'm still getting far under Apple's 12 hour estimate when surfing the web even at 50% rather than 75% brightness. Anyone else out there having these issues or that could help?


MacBook Air (13-inch Mid 2013), OS X Mountain Lion (10.8.4)
  • LowLuster Level 6 Level 6 (12,050 points)

    The apple estimate of battery life time is just that, a Estimate. In the real world it could be longer, by a little, or much shorter depending on how you are using your mac.

     

    Doing a full discharge is not suggested for Li-Ion batteries so I suggest you don't do that again. The battery is already calibrated from the factory. Fully discharging it will only cause harm to the battery.

  • Hyper7Death Level 1 Level 1 (0 points)

    Thank's for the prompt reply. I realized that the microprocessor simply didn't calculate the time correctly at first. Now it's reading around 11 hours and 22 minutes.

  • Kyle531 Level 1 Level 1 (0 points)

    Hey Hyper,

     

    I'm suffering from the same problem. I've been wondering if there was something wrong with my battery because some people are hailing it a huge success (Mashable and others).

     

    I'm putting it to the test today as I have been using it non stop at work. This weekend I will be putting it through the video test as I've heard you can watch 2 movies and 2 tv shows before it dies.

     

    I did hear rumor that becuase I have the Core i7 that it may cause reduced life. I also ended a lot of background programs like Evernote, Dropbox, and Adobe creative cloud. Another thing is that this is my first Macbook and I'm not sure how to judge the battery life. I've been using an iMac for about two years now.

     

     

    @LowLuster, I've never heard about it hurting the battery because Apple and many other's suggest doing that calibration. A lot of blogs recommend doing it the day that you get the laptop. You may know way more about batteries than I do so I'm definitely not arging - just saying what I read.

  • LowLuster Level 6 Level 6 (12,050 points)

    Apple does not recommend doing a calibration on the newer macbook pros that have a non removable battery. Only on the older mac notebooks that had a removable battery.

     

    http://support.apple.com/kb/HT1490

     

    Read the section on Mac notebooks with non removable batteries.

     

     

    Portables with built-in batteries

    Current Apple portable computer batteries are pre-calibrated and do not require the calibration procedure outlined in this article. These computers use batteries that should be replaced only by an Apple Authorized Service Provider.

  • Kyle531 Level 1 Level 1 (0 points)

    Well that's not good. Oh well, I'm sure people let their batteries die all the time. I'll just make sure to avoid doing it.

     

    I still don't like that I'm not getting close to what Apple claimed the new MBA 'could' achieve. I'd be happy with 10 hours on the web but I'm thinking I'm going to max around 7 or so.

  • LowLuster Level 6 Level 6 (12,050 points)

    In my opinion anyone that runs a notebook out of battery power is very foolish. First it is not good for the battery and second that is how you corrupt the os and programs and lose data.

     

    It's not hard to plug the thing in when the battery get to 10-20% and if that is not an option then you need to stop using it until you can plug it in.

     

    Once below that 10% the system could shut off at any time. This is even more likely on a slightly older notebooks as the battery loses charge capacity over time and that might not be reflected in the percentage or time left being reported.

  • Kyle531 Level 1 Level 1 (0 points)

    Well now I'm really nervous... so I just hurt its potential battery life.

  • LowLuster Level 6 Level 6 (12,050 points)

    Doing it once or twice on a new system won't really hurt it. It's just not a good thing to do over and over.

  • Hyper7Death Level 1 Level 1 (0 points)

    Well the one thing I've noticed is it can be really sporadic. When I woke it from sleep, it was cut down immediately from 11 hours remaining to 5 hours but I'm sure it's just a bug in the calculation seeing how 5 minutes after the drop, it is relaying over 7 hours remaining. I was also under the impression that the newer Lithium Polymer batteries weren't affected by the calibration either since they lack the memory of older Lithium batteries and I'm sure letting it drain until it puts itself to sleep once a month shouldn't be bad for the battery. The firmware makes sure that there's still charge left even if you can't boot it

  • LowLuster Level 6 Level 6 (12,050 points)

    Li-ion batteries do not like to be discharged all the way. That has nothing to do with memory of the battery cells.

     

    Once a li-ion battery is fully drained it will never hold a charge again so there are safeguards built into the battery so that shouldn't happen. But like anything else those safeguards can fail. Running it down to zero percent repeatedly can over time cause the battery to fail sooner then it normally would.

  • Kyle531 Level 1 Level 1 (0 points)

    Ya, It can't be bad to do it once in a blue moon. I'm a college student and I see how people treat their Macbooks...I've seen them bent before. I'm sure the battery can handle getting drained once. But, now that I know it can harm the Lithium battaries, I will not be draining it again!

     

    As for the longevitiy of the battery, it lasted while I was using it all day at work (about 7 hours and 40 minutes). I'm at home and it has about 24% left.

     

    Tomorrow I'm going to break it down by hour and see how long it can go. I just want to make sure it can handle my fall college schedule. I hope to get closer to 9-10 hours before I plug it back in.

  • Gesen Level 1 Level 1 (0 points)

    I've got the 13 inch model with the 1,7GHz i7 and 8GB RAM. I'm getting just under 8 hours at 100% charge. Never seen the battery indicator go over 8 hours.

  • PlotinusVeritas Level 6 Level 6 (14,710 points)

    I love FIREFOX and loathe safari, but it turns out firefox is a real hog on battery life.

     

    Ive seen several reports of people getting 13.2+ hours life on their new AIRS.

     

    Im typing on one now, batt life is incredible.

  • PlotinusVeritas Level 6 Level 6 (14,710 points)

    You are the 4th person ive heard getting greatly reduced batt. life with the I7 processor.  Which is why I didnt want it. Also the I7 (as to be expected) is running hotter.

     

    There is almost no need I dare fathom i could see needing the I7 for any application most anyone uses, since its not that big a difference in speed, but a big drain in batt life.  Not a fair tradeoff logically I can discern.

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