13" 5 hours battery: should I take it back?

Discussion in 'MacBook Air' started by Vazkor, Jul 23, 2011.

  1. macrumors member

    Joined:
    Oct 20, 2006
    #1
    Hi ppl, just bought my 13" i5 and even with full charge it never shows more than 5 hour battery life, sometimes just 4. Will it improve after a few charge/discharge cycles or should I take it back?
     
  2. MRU
    macrumors demi-god

    MRU

    Joined:
    Aug 23, 2005
    Location:
    Ireland
    #2
    Do a full battery calibration first.

    Plug in the power adapter and fully charge your battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
    Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
    Disconnect the power adapter while the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, the low battery warning dialog appears on the screen.
    At this point, save your work.* Continue to use your computer; when the battery gets very low, the computer will automatically go to sleep.
    Turn off the computer or allow it to sleep for five hours or more.
    Connect the power adapter and leave it connected until the battery is fully charged again.






    Install coconut battery to check on the condition of your battery to make sure it's retaining it's full charge.
     
  3. macrumors 6502a

    Joined:
    Jun 28, 2011
    Location:
    Canada
    #3
    You won't get better battery life if you switch it up for a different one. My 11.6-inch is 2.5 to mayyyybe 3.5 hours of battery life with general usage with Wi-Fi on and light on very low.

    Battery life is simply poor on these things. :-/

    As per what Apple's website says, battery calibration is not needed for the Macbook Air. However, should you want to treat your battery properly, make sure you bring it down to about 2-3% charge, and then charge it up fully to 100% and leave it plugged in for a bit longer than that. Then use it from there. Do that a couple times and see if things improve.

    I know that my Air drops from 100% down to 98% almost instantly when I unplug it. It takes about 1-2 minutes and bam it's down. Then it drops by 1% every 1.5 to 2 minutes of use. So I get about 3 hours of use out of it, maybe a tiny bit more if I'm lucky. Rated for 5 hours. Kind-of disappointed... but it's not bad so long as it doesn't deteriorate badly over the next couple years.
     
  4. macrumors member

    Joined:
    Jul 20, 2011
    #4
    The only way you'll get more than 5 hour battery is if you let the macbook air idle on the desktop with no apps open. I have the i7 macbook air and with first use it didn't show a high battery life (4 hours), but with the 2nd cycle it showed 7 hours fully charged. That is if I don't have any apps open.
     
  5. macrumors G5

    gnasher729

    Joined:
    Nov 25, 2005
    #5
    All depends on what you are doing. How bright did you set the screen? You realize that screen brightness is light and producing light takes power?
     
  6. thread starter macrumors member

    Joined:
    Oct 20, 2006
    #6
    I'm not talking about real world usage, I know I'll never reach the advertised battery lifetime but I'd expect at least the battery icon on the system bar to show a 6-7 hour battery life. Well if you say it's normal I'll deal with it, love the machine it's dead silent and screaming fast at the same time.
     
  7. macrumors 6502a

    Joined:
    Jun 28, 2011
    Location:
    Canada
    #7
    I'm doing a bit more in-depth testing on my machine again to be certain of my battery life. It appears to be doing slightly better with the first fiew charges... but maybe time just felt like it was going by quickly at first.

    Anyways, I'm keeping track of how much % is lost per 10 minutes at various intervals of time. When I have the time I'm going to test per 60 minutes all the way through battery life at low screen settings with Wi-Fi on, attempting to mimic Apple's claimed time: Apple claims 5 minutes (approx) by browsing with everything on low (only browsing) 25 sites. So I would say refresh the browser 100 times (4 times per site, with 25 sites total). And that will let you know if you have the correct battery life. Flash off of course.

    To do a short version of this, test it for 30 minutes and count the % at the start, and the % at the end. Do this twice (so 60 minutes total). Do it once from 95%, and once from 45%. If you have time, do 90 minutes: once at 95%, once at 65%, and once at 35%, to get a general idea without spending a ton of time. Just spend 30 minutes on each of those intervals, and browse the internet slowly with your screen on very low.

    Then you just take the average of the 3 (assuming they're similar amounts of lost % within the 30 minute time-frame), and you have how much % battery life is used per 30 minutes. Then just figure out (basic math) how long your battery should last.

    Currently browsing at 85% brightness I'm getting 4% lost per 10 minutes on my 11-inch. So that amounts to 4.16 hours total, assuming this remains true all the way through. However, my battery might seem to go quicker when I hit say... 50%. I might start to record losing 6% per 10 minutes... who knows. So it's a good idea to test it at different intervals of the battery. So later on I'll do this same test at 40%, 30%, and so on, and see if it remains true.
     
  8. macrumors member

    Joined:
    Jul 21, 2011
    #8
    For what it's worth, my i5 is at 96%, bit of web browsing, wifi on, screen on minimum brighness and the battery is showing 7:13 remaining.
     

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  9. macrumors 6502a

    Joined:
    Jun 28, 2011
    Location:
    Canada
    #9
    Either you have a godly Macbook Air, or all Airs seem to get it wrong at high charge. :-/

    I get a really high number read to me at low settings to start (somewhere between 6 and 7 hours), and then it drops down super fast as the % drops to 90%.

    At 76% remaining I have 4:39 read to me. Just a second ago it said 3:30. So I don't know how it's really judging the time.
     
  10. macrumors 68020

    MattZani

    Joined:
    Apr 20, 2008
    Location:
    UK
    #10
    I'm calibrating my battery right now, yeah they might not need it but it's all I know and won't hurt it. I'll see how my next usage goes after it's fully charged and rested.
     
  11. macrumors 6502a

    Joined:
    Jun 28, 2011
    Location:
    Canada
    #11
    I'm a really picky user as well, so I am in a similar boat to you. I am a bit peeved by the battery performance. It's quite finicky and I'm undecided. I have until the 4th or 5th of August to make an exchange anyways, so I can spend my vacation playing with the Air, and if I determine there's a real battery issue, then I can get my exchange just fine. However at this point, I doubt I will need to make an exchange; I'm also quite happy with my screen & hard drive: I got a Samsung SSD, and Toshiba screen. Decent enough mix.

    You play any youtube videos, intense applications... or anything really... and the battery goes like mad. However I'm really trying to do a consolidated test with only word processing and basic web browsing (to imitate when I would really be doing when doing work at school, where my battery life truly matters).

    If I were to say... get only 3 hours on low light and word processing... then yes, I'd be returning my Air. So comparatively for a 13-inch, I'd say you should have a minimum standard as well (based on your 7 hour rating).

    I'm looking for 4 hours and 30 minutes of battery life for productivity (totally acceptable), and hopefully 5 hours if it's doable. I'm fine with 2-3 hours if it's youtube/games/other things.

    I'm noticing while I'm viewing my battery (periodically), that my battery life really slows down and preserves itself when I'm simply typing and doing super basic stuff. The moment I load a basic youtube video, or view the app store, or start shifting around using hand gestures, things get bad with battery life.
     
  12. macrumors 68020

    MattZani

    Joined:
    Apr 20, 2008
    Location:
    UK
    #12
    With ONLY Safari open full screen with 3 tabs, wifi, brightness around 85% I'm getting 3:33 remaining at 94% :/
     
  13. macrumors 6502

    Joined:
    Jul 5, 2011
    #13
    Make it down to 50% bright and see if you have improvements on battery. Brightness on display panel use more battery than you'd imagine.
     
  14. macrumors 6502a

    Lord Appleseed

    Joined:
    Nov 7, 2010
    Location:
    Apple Manor
  15. macrumors 68020

    MattZani

    Joined:
    Apr 20, 2008
    Location:
    UK
    #15
    But I like it bright! Got it to about 60% now, battery skips from 2 hours - 5 hours remaining, may have to just time it.
     
  16. macrumors 68020

    MattZani

    Joined:
    Apr 20, 2008
    Location:
    UK
    #16
    been watching 4OD for about 30mins which is flash I think, battery is now at 60%
     
  17. macrumors 65816

    Gemütlichkeit

    Joined:
    Nov 17, 2010
  18. macrumors 68020

    MattZani

    Joined:
    Apr 20, 2008
    Location:
    UK
    #18
    I think you just need to stop worrying so much, I've got a solid 3 hours so far and I'm at 18%, this includes 4OD, Twitter, Transmission and updating iTunes etc so fairly happy, probably gonna get about 4 hours. Hopefully it will get better as the cycles get into it.
     
  19. macrumors 68030

    Joined:
    Jun 19, 2010
    Location:
    Ft Lauderdale
    #19
    A new disease spreading here: MBA hypochondria .......
     
  20. macrumors newbie

    Joined:
    Jul 24, 2011
    #20
    Count me in on the MBA hypochondria. New 13" i5 and I'm in the 4.5-5 hour range with what I consider 'normal' use.

    One test I read about in another post that would help everyone to benchmark somewhat consistently is www.reallyrefreshing.com (abbreviated RR.com below), which does basically what Apple does in their battery testing (or at least close).

    All they do is refresh your browser to a new site every minute for as long as your battery lasts, so you set your brightness, etc. before starting the test and then let it run (overnight is easiest) until it fails, and the site keeps track of how long the test lasts before you go offline. Also use the app caffeine to keep your screen from sleeping during the test as that obviously would skew things.

    In my first test, I ran with 50% brightness (screen & keys) and also ran Spotify in the background with the volume set on 3 bars. The rr.com test bugged out on me after ~1.5 hours (it is in beta and unfortunately a little buggy). I noticed the test had died after about ~4 hours and then started it again. Spotify played the whole time.

    In combination, my battery lasted 4:41.
    All 4:41 of this was with Spotify streaming with the volume on 3, and ~2.25 hours of it was with the RR.com web test running simultaneously.

    In total, I think that's probably pretty good as I had my speakers on the whole time. I'll run the next test tonight with no volume and the rest of the settings the same and see how long it lasts.

    I'd be interested to see how other people's MBAs perform using the RR.com test. If you run the test, please post back here with your results.
     
  21. macrumors member

    Joined:
    Jan 16, 2011
    #21
    In all the situations where I would find myself without a power supply, I would also not have available, or not need wifi (lectures at university, on an airplane or train, waiting in a random spot etc). Wifi is quite a big battery drain so I would consider that as well.
     
  22. macrumors 6502a

    Joined:
    Feb 3, 2011
    #22
    Welcome to Sandy Bridge, underpowered IGP and reliance on TurboBoost to make up for it, equals higher battery drain. This machine would have been perfect with an i3/320M combo, too bad it never happened because of the legal quagmire Intel created.
     
  23. macrumors member

    Joined:
    Sep 25, 2008
    #23
    I'm getting about 6-7 hours of real world usage. Brightness set to 2-5 bars. Closed safari, use firefox with noscript. Mail open, terminal sshing. A little vlc for mp3 and itunes for copying mp3 to an ipod. Bluetooth off, itunes/helper off. Just did a drive to vegas with phone tethering, about a 6 hour drive. Show's 2 hours left. Had to eat, stop for gas and stuff. My 2010 model was getting close to 9 hours when I first got it using it for light browsing.

    EDIT: 13" i7 model.
     
  24. macrumors newbie

    Joined:
    Jul 24, 2011
    #24
    This is an honest question (in case it sounds snarky), but does TurboBoost really come into play for normal non-video web browsing?
     
  25. macrumors 6502a

    Joined:
    Jul 24, 2011
    #25
    Is Firefox easier on the battery than Safari? I like all three browser (Safari, Firefox, Chrome), tbh., so if one is better on the battery I'd just start using it.
     

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