Only 8 hours at 100%?

Discussion in 'MacBook Air' started by Dominio, Jun 24, 2013.

  1. Dominio, Jun 24, 2013
    Last edited: Jun 24, 2013

    macrumors newbie

    Jun 14, 2013
    I gave my MBA it's first full charge and at 100% I have an estimated 8hours 52 mins usage left.

    Nothing open except Safari and browsing facebook and Macrumours.
    I have a base 13" with brightness set at middle.

    Not doing anything demanding, yet the battery life is a far cry from 12 hours.

    Also, I appear to be losing 1% every 5 minutes through light web browsing (no flash).

    Is this normal after one charge? or should I change it?

    Also, how would I be able to tell whether the model I have is a 2013, and not a last remaining 2012??
  2. macrumors 65816


    Jun 23, 2010
    Miami, FL
    Whats your model number?
  3. macrumors regular

    Jan 31, 2011
  4. thread starter macrumors newbie

    Jun 14, 2013
    a1466 emc 2632


  5. macrumors regular

    Jan 31, 2011
    Then it's definitely the 2013.
  6. Guest


    Apr 6, 2010
  7. macrumors regular

    Apr 15, 2013
    Houston, TX
    In my experience, the estimate is wayy off. Like 2 hours off and plus its constantly changing. Use the laptop and time how long you use it. You should be getting 11+ hours with light use.
  8. macrumors 68040

    Feb 13, 2012
    Perth, Western Australia

    You realise that is an ESTIMATE and has no way of knowing how your power consumption will vary over time?

    Also, when you are on ~100%, the battery has not discharged much at all and it has not had a lot of statistcs to base its estimation on.

    Stop looking at the meter, and time it.

    Also if it is brand new, the first spotlight run(s) will have skewed the stats on it with regards to battery estimates.
  9. macrumors newbie

    Jun 10, 2013
    Let me know how that goes. I am exchanging mine today, bc 7 hours is a far cry from the 12 hours most ppl here have!
  10. macrumors 6502

    May 27, 2013
    If this is the first run it's doing lots of things in the background. Add in it takes a couple cycles for it to fully understand how much charge the processor is using vs the battery capacity and that makes sense. Wait a couple cycles, it'll say 12-13.

    REMEMBER, that's just an estimate time... the battery life ESTIMATE is a far cry from 12, not the actual battery life itself.

    As for whether it's a 2013 not a 2012, you should have two mic holes on the lefthand side of the mac after the headphone jack, not 1.
  11. macrumors 603


    Sep 19, 2003
    Canada, eh?
    Exactly. Battery life is an inexact science given the varying conditions you put your computer through each day. And especially when the machine is brand new:

    (a) the power management system has not calibrated itself yet
    (b) the battery takes a few "practice" cycles to get itself to full charge
    (c) the OS is doing things in the background for the very first time, like indexing your entire hard drive for Spotlight.

    So don't worry about what the battery meter says, and give it a week or so of use before you start to worry.
  12. macrumors regular


    Nov 15, 2012
    Yep yep. Sometimes I get estimates over 20+ hours.
    But Apple estimates are definitely true, you will get around 12 hours if on the same conditions as their tests.


    Apple calibrates ALL their built-in batteries, and SPECIALLY new machines. Calibration is only required for old computers with removable batteries.

    Quoted from

    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.


    MacBook (13-inch, Late 2009) and later
    MacBook Air

    MacBook Air (all models)
    MacBook Pro

    MacBook Pro with Retina display (all models)
    MacBook Pro (13-inch, Mid 2009) and later
    MacBook Pro (15-inch, Mid 2009) and later
    MacBook Pro (17-inch, Early 2009) and later

    Read their article:
  13. macrumors 603


    Sep 19, 2003
    Canada, eh?
    Ah. I stand corrected. I still own one of those older machines with the removeable battery.
  14. macrumors regular


    Nov 15, 2012
    Oh! I still member the day when Apple switched from removable to built-in, a lot of people thought it was the end of the universe, lol, but built-in have more advantages, such as already coming pre-calibrated.

    How often do you calibrate your battery? I've heard it has to be done periodically.
  15. macrumors 603


    Sep 19, 2003
    Canada, eh?
    I don't make a conscious effort of it, but since the instructions are basically to run it all the way down, I do let that happen every once in a while. Once a year maybe. The battery definitely holds much less charge now than it did when I got it in 2007.

    I deliberately bought the last generation before they went to built-in, thinking I would be at an advantage because I could replace my battery anytime I wanted. However, now that buying a replacement battery is finally justifiable, I find I'd rather just replace the whole thing with, say, a new MacBook Air or Retina MBP.
  16. macrumors regular


    Nov 15, 2012
    By the way.. estimations at 100% are 100% unreliable. :)
    Let it drop at around 80% to get much accurate readings.



    Say, If a MBA runs out of cycles, do you think that Apple would change the battery? I know they replace them if within the warranty if they don't hold charge, but what about a paid service?
  17. macrumors 6502

    Sep 23, 2012
    You can get a battery swapped out for $130 at the Apple store.
  18. macrumors G4

    Oct 14, 2005
    Did you install Adobe Flash? Apple's battery tests are done without the browser being able spin cycles on that, IIRC.
  19. macrumors member


    Oct 8, 2012
    Arkansas, USA
    After a couple of full cycles, I'm still getting rather terrible battery life on my 13" 2013. Used it today (2/3 brightness, just using Evernote during a meeting), and barely made it 6 hours. Given that I was planning on this MBA replacing my rMBP (which gets 4-5 hours easily), I'm fairly certain I'll be returning the MBA.
  20. macrumors 6502

    Nov 21, 2010
    I've been running mine nearly constants since 11 am. It's currently 8:45pm and I'm showing 17% left w/ 2:14 remaining. I've downloaded and watched two HD movies from iTunes at about 80% brightness and surfing the web at about 55%. So I've been using the machine for 9 hrs 45 minutes and have over two hours left estimated giving pretty darn close to 12 hours. I would hope to get 12 just doing light duty like surfing, email, and some text edit type stuff. I'm amazed at the batter life after downloading and watching two full length HD movies.

    I think you should exchange yours for another and see if it works out better.
  21. macrumors 6502a

    Oct 8, 2012
    I also have been getting fantastic battery life on mine. There are times when I probably will get more in the range of 8-10 rather than 11-12, but that's still superb.
  22. zephonic, Jun 27, 2013
    Last edited: Jun 27, 2013

    macrumors 6502a


    Feb 7, 2011
    South Bay, Los Angeles
    I have the new 13" 1.3GHz with 4GB RAM and 256GB SSD. I think I have been averaging 8+ hrs. I might have hit 10 hrs. on occasion, but I don't think I got to 12.
  23. macrumors member

    May 21, 2009
    I think we need to let them bed in for a few days with real use. Last night I was getting 6 hours, today I've been going for 3 hours solid on Photoshop and have 7 hours left. And this is heavier than web browsing. Bluetooth is on as is wifi.

    As for the question over the battery calibration, from what I'm aware of this is not the same as the OS calibration, they are two things. It's the same as the signal software on your phone, it's an interpretation. For the battery use it grows in quality as you use it.

    Certainly true for my MBP.

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