Battery Life.... Should I be concerned

Discussion in 'MacBook Air' started by stakis, Apr 7, 2008.

  1. stakis macrumors member

    Joined:
    Oct 25, 2007
    #1
    Hey Macrumorists,

    I just wanted to get some opinions from some of you on the MBA battery life I'm experiencing.

    First, my MBA is about 2 weeks old and its a week 11 MBA... When I run coconutbattery, I'm given a max capacity of 4949mAh which is 97% health, and 12 load-cycles.

    the other day, I was using my MBA at the office.... I had a usb hub pluged in with my mighty mouse and ethernet adapter pluged in... wifi was off. and screen brightness was set to about 5 or 6 blocks...

    In my session I was surfing the web... (basically reading all the techblogs... I watched 2 5 minute youtube vids)

    I downloaded a 300 meg file with bit torrent, and then downloaded install files for Ubuntu (700megs)

    the last thing I did was install ubuntu in VMware.

    after all this... I was left with an uptime of 2hrs and 45 minutes.

    I haven't been monitoring my battery life other than today, but I figured that I would've had at least 3.5 hours... given that the install of Ubuntu might have been a high cpu thing....

    do you guys think this is normal?

    PS... I'm also using coolbook to under-volt the CPU....
    :confused:
     
  2. Zwhaler macrumors 603

    Zwhaler

    Joined:
    Jun 10, 2006
    #2
    Im not so sure about your real world restults, but I wouldnt be too concerned with 97% battery health. Dropping below 85 or 80 is bad, but in your case, you are fine.

    Not sure if this applies to you, but here is something I noticed while using a MacBook. Battery time remaining is indicated by the amount of power being used at the moment. For example, if you are utilizing all of your MBAs power, and the time remaining says 2 hours (example), the second you finish and revert to using only 25% of power, then the battery time will jump back to something much higher.
     
  3. ayeying macrumors 601

    ayeying

    Joined:
    Dec 5, 2007
    Location:
    Yay Area, CA
    #3
    That seems perfectly normal. When I had my MBA, I got around 2.5-3 hours of battery life with CoolBook (and running stuff like virtual machines).
     
  4. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #4
    I experience the same

    Hi everybody.


    I experience the same :

    4860mAH on max charge
    Health 95%

    I am not using undervoltage but with very light use e.g. Safari/Mail/aMSN, no more than 3 hours which is very disappointing, (wifi/airport disabled, just Ethernet USB adapter)

    and which is very anoying : up to 10 hours to charge the battery....

    how long does it take for you ?
     
  5. RedAbundance macrumors member

    Joined:
    Apr 2, 2008
    Location:
    New York, NY
    #5
    lol it is very annoying indeed that the battery takes FOREVER to recharge. i remember it didn't take more than 3 or 4 hours to charge my macbook pro.
    i'm getting on average 4 hours on my air for surfing the web and light video watching, and it takes about 8 hours to recharge fully.
     
  6. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #6
    I get 5 - 6 hours of wifi surfing. To charge is about 3 or 4 hours (4 hours when totally out of juice).
     
  7. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #7

    some people get more than 5 hours and just 4 hours to recharge, some other no more than 3 hours and more than 8 hours to recharge...

    so there is an issue, it is crystal clear. :(
     
  8. stakis thread starter macrumors member

    Joined:
    Oct 25, 2007
    #8
    I've read on other posts that others have been getting better results after calibrating the battery.... is this simply done by letting the computer die out completely and then charge it back up to 100%... or is there a specific method in re-calibrating the battery?

    My charge time seams to be about 4 hours....


    man, I wish I was getting 4 or 5 on wifi surfing.... sucks that they aren't all consistent...
     
  9. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #9
    After a battery calibration it is the same, but I have noticed that :

    with full recharge :

    3H remaining with ethernet adapter, airport deactivated
    4H30 without ethernet, airport still deactivated
    3H30 without ethernet, airport activated

    results are not quite accurate, let's say +- 20 min but ethernet adapter sucks :mad:
    I am not quite happy with that, almost 50% more battery life without the adapter...:rolleyes:

    3H30 with airport is still disappointing.

    After calibration, battery charge seems to be near 5H, but it was in the night so just a calculation from the 80% I get before sleeping.
     
  10. stakis thread starter macrumors member

    Joined:
    Oct 25, 2007
    #10

    I was thinking there was something fishy with that Ethernet dongle... I mean, theoretically you'd think that ethernet has way more power savings than wifi, but what most people don't realize is that the ethernet isn't being operated by a chip on the motherboard, rather through USB... so that must take some kind of CPU power or voltage to make the bridge.....

    I'm going to try doing the same kind of test as I mentioned in my original post and this time use wifi... see what the results are and I'll post back here.
     
  11. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #11
    Any of you with really bad battery time ever bother to give your Macbook Air 14 hours of charging when you first purchased it?

    I thought it was common knowledge to do that - it give your battery a longer life too.

    I get on average 6 hours of wireless surfing and stuff, and no I don't bother dimming my screen or anything like that.
     
  12. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #12
    I've recharge full 100% the battery before installing the MBA. Yes it is a common knowledge and I was aware about that.
    I don't want to deal with WiFi for health safety reasons so I think the MBA is not for me because ethernet gets too much ressources.
    I have no moneyback warranty, I have to sell my MBA:(
     
  13. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #13
    Wifi??

    What's the problem with Wifi?
     
  14. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #14
    wow, huge question, just try wifi+health in google.
    Are you sure you want to have a microwave on balls ? Maybe everything is fine right now, but in 5, 10...30 years ?
     
  15. joegomolski macrumors 6502

    joegomolski

    Joined:
    Apr 28, 2006
    Location:
    So CA
    #15
    Here's something to think about. When the MBA is very active, doing this and that. The battery gauge software, will be looking at current usage, and will determine remaining battery life as if that activity will continue.

    To test this check your battery life, and then dim your display to it's lowest setting, when the battery gauge then examines remaining life, it's calculation will be based on the MBA's reduced usage.

    When you begin to use the MBA more intensely, you'll see the time remaining drop.

    Set the MBA to it's lowest level of activity and the battery life will go up.
     
  16. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #16
    So I guess you don't own a cell phone, have a satellite dish, listen to the radio or live near any overhead powerlines either?
     
  17. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #17
    If you read carefully your GSM owner manual you should know that they told you to use it as far as possible from yourself using a "hand free kit" if possible.
    A satellite receiver just...receive, no emissions, the wave we receive from sat is so low that you need big parabols to concentrate it.

    A lot of people misunderstand the way the radio waves works and there is a strong believe that FM is the same that WiFi, if you are happy with that it is your own health, but I don't like the idea to have fulltime microwave emissions in my home...
     
  18. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #18
    For guys that get more than 5 hours of use can you tell me :
    *how is the dimmer for the screen light : full, half ?
    *same question for the keyboard retro light
    *do you use the MBA really during thos 5 hours or sometimes the screen is sleeping ?
    *do you have any USB devices connected ?
    *do you surf with airport activated ?

    I can't get more than 3H30 of surf and I need to reduce screen brightness to get that, otherwise it is between 2H50 and 3H00 with brightness close to max.

    I want to know if my battery has an issue or if the MBA is just not for me...

    thanks.
     
  19. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #19
    I think you've got a battery issue. My screen is set to mid to high brightness, back light keyboard is automatic and I have no usb devices connected, just wifi activated and bluetooth deactivated since I don't have bluetooth devices. And I don't put my MBA to sleep, I deactivated that function.
     
  20. stakis thread starter macrumors member

    Joined:
    Oct 25, 2007
    #20
    Well it looks like I'm till only at the 3:15 minute mark... Screen brightness at half way using Wifi...

    I'd also like to hear what you folks with 5 hour times are doing... i'm determined to get this juice flowing better....

    I did however reset my SMC and calibrate my battery, so I don't really know what else I can do...
     
  21. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #21
    I really do nothing special at all, I've got bluetooth disabled and that's all. The screen brightness is set to half way and that's it. I get 5 to 6 hours no problem - I'm so used to my Vaio UX giving me 3 hours which really bugged me.
     
  22. Sesshi macrumors G3

    Sesshi

    Joined:
    Jun 3, 2006
    Location:
    One Nation Under Gordon
    #22
    I get about the same as the Air (3:30 + sleep / hibernate time) when I use the extended-battery UX under similar circumstances. Mind you, I'm not as dilligent on the UX about turning off WLAN when I don't need it. Hammering it, the machine goes down to about 2:40.

    Besides, you can do this with the UX:
    [​IMG]

    And this with the TZ:
    [​IMG]

    1.3 Sony kilograms would get you an 11-hour TZ or a 14-hour UX.
     
  23. MarkF44 macrumors member

    Joined:
    Apr 6, 2008
    #23
    I've returned my MBA back to the support, some people get 5 hours some others no more than 3 hours, it is an issue.
    I have to order another MBA or switch to a more reliable laptop...MacBook Pro ?
     
  24. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #24
    They (Apple) needs to replace your battery, there is clearly something wrong with a batch of MBA batteries - right now, I'm getting over 6 hours of remaining battery life and I've already been using my MBA for 20 minutes. My screen is set to half brightness.
     
  25. aussieinrome macrumors regular

    aussieinrome

    Joined:
    Apr 5, 2008
    Location:
    Rome, Italy.
    #25
    Hahaha, great response.
     

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