Why am I no longer getting 12 hours of battery from my 2014 Air?

Discussion in 'MacBook Air' started by Jacoblee23, Apr 10, 2015.

  1. Jacoblee23 macrumors 6502a

    Joined:
    Nov 10, 2011
    #1
    I have turned off all the necessary things that drain the battery and now when I charge it to 100% it displays that it has only a little over 7 hours of battery life to go. I got my macbook back last June and haven't even used it a whole lot. Is my battery messed up? Will Apple replace it?
     
  2. Airboy1466 macrumors regular

    Airboy1466

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    Feb 23, 2015
    #2
    If your cycle count is under 1000 AppleCare will replace the battery
     
  3. Santabean2000 macrumors 68000

    Santabean2000

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    #3
    Do you use it with the power plugged in? Sure way to kill the battery health if you do.
     
  4. velocityg4 macrumors 68040

    velocityg4

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  5. ZBoater macrumors G3

    ZBoater

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    #5
    Huh? :confused:

    ----------

    How many hours do you actually get?
     
  6. Santabean2000 macrumors 68000

    Santabean2000

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    #6
    When you run a MacBook when charging, the health of the battery suffers. Better practice is to charge you MB when not in use and unplug it when the green light comes on (when using our just finished charging).
     
  7. David58117 macrumors 65816

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    Jan 24, 2013
    #7
    I thought this was true for older types of batteries, but not the type used today?
     
  8. ZBoater macrumors G3

    ZBoater

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    #8
    Um, that's ok. I'll just follow Apples advice instead.

    https://www.apple.com/batteries/

    Thanks for your suggestion though.
     
  9. ctyrider macrumors 6502a

    ctyrider

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    Jul 15, 2012
    #9
    That's nonsense. Modern batteries do not suffer when plugged in.
     
  10. PhiLLoW macrumors 6502

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    May 31, 2014
    #10
    What?? Stop spreading myths like this.


    If You constantly drain your battery and recharge it it's worse für the battery.

    Charging + working on your Mac or Smartphone is perfectly fine.

    If you're at home and your device is at 100% it's even better to keep it connected to the power outlet ( less charging cycles. But it won't hurt the battery )
     
  11. Jacoblee23 thread starter macrumors 6502a

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    Nov 10, 2011
    #11
    Hmm. So I restarted my computer and now it shows at 100% that I'm getting between 12-13 hours. I did download coconut battery and I think it said I had 96% capacity or so left?
     
  12. Santabean2000 macrumors 68000

    Santabean2000

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    Nov 20, 2007
    #12
    Funny, Apple's no 1 tip for looking after your battery? Prevent heating it up. Guess what a the fastest way to heat your MacBook... run it while charging. [esp if doing intensive work]

    "In order to squeeze as much life out of your lithium-polymer battery, once your laptop hits 100 percent, unplug it. In fact, you should unplug it before that."
    http://www.wired.com/2013/09/laptop-battery/
     
  13. ZBoater macrumors G3

    ZBoater

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    #13
    Really? You do realize that in the 21st century, Apple laptops stop charging when they reach 100% even if their left plugged in, right?
     
  14. motrek macrumors 68020

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    Sep 14, 2012
    #14
    It doesn't matter if the CPU heats up, i.e., during intensive work. Look at a teardown of a MacBook. The CPU isn't near the battery.

    When Apple says avoid temperature extremes they mean don't leave your MacBook in your car in the sun on a hot day, stuff like that. Normal use like charging and using the laptop won't lead to extreme temperatures.

    If you use a MacBook while its plugged in then it gets the electricity it needs to run from the wall instead of the battery. Which means it doesn't put wear on the battery, which means the battery will last longer.

    MacBooks should be plugged in whenever it's convenient, if you want to maximize battery longevity. Running on battery power is what wears them out.
     
  15. joeblow7777 macrumors 601

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    Sep 7, 2010
    #15
    That's not true at all. It's good to let the battery get some exercise, so to speak, from time to time, but in general reducing battery cycles is good for the battery. Every time you discharge and recharge your battery you wear it out just a little. That's why expected battery lifespan is measured in cycles. When the computer is running off of A/C power, you aren't using battery cycles. I've found that the best approach is to plug in your computer whenever it's convient, and run it off the battery when you need to.
     
  16. Santabean2000, Apr 11, 2015
    Last edited: Apr 11, 2015

    Santabean2000 macrumors 68000

    Santabean2000

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    #16
    Ummmm. Yes. Read the article linked. You might understand why having kept at 100% is not optimal.

    In a MacBook the aluminum case acts as a heatsink. The hotter everything gets inside the warmer the whole MacBook gets. It only has to be warmer than 35deg C inside to start affecting battery quality.

    I suggest that you run iStat or even just check the 'About' section of the MacBook. See for yourself the battery health - watch it deteriorate when consistently run from the charger.

    No dramas if you don't believe me. Your battery's death.

    1000 cycles is more than you could get to even if you tried (in the typical life span of a few+ years). It's the battery quality that you need to monitor, not the number of cycles.
     
  17. xylitol, Apr 11, 2015
    Last edited: Apr 11, 2015

    xylitol macrumors regular

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    Finland
    #17
    So, keeping your laptop plugged in all the time (who does that?) will kill its battery faster than being anal-retentive about monitoring battery charge percentages.
     
  18. joeblow7777 macrumors 601

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    Sep 7, 2010
    #18
    You may find this odd considering the nature of this forum, but I don't actually own a Mac, so I can't follow your suggestion.

    But what I do have is a fair amount of experience with other laptops and devices powered by Li-ion/Li-polymer batteries, and I've never had to replace a device's battery due to loss of capacity before upgrading the device itself. On my Windows PCs I run "Battery Bar" which (perhaps similar to iStat) shows the battery's current wear, so I can tell quite easily if my usage is causing harm.

    The fact of the matter is you're right that a healthy battery should provide enough charge cycles to get though at least a few years before loss of capacity is significant, even if you use a battery cycle per day. And yes, ALWAYS keeping your battery at 100% does itself cause wear. The best possible thing you can do for long term battery maintenance is to keep it's charge between about 40 and 80% (as even the article you linked to says). Some manufactures (not Apple) actually actually provide a setting that makes the battery stop charging at 80% so that you can leave it plugged in as much as you want and not cause wear by keeping it maxed out OR using discharge/charge cycles. This strategy is also suggested by the article.

    However, I still maintain that provided you do use the battery on a fairly regular basis, using the computer plugged in and fully charged results in less wear over time than constant battery use. The idea that mostly using A/C power does more harm than good is based on the misconception or outdated notion that batteries overcharge or overheat when plugged in at 100%.
     
  19. Santabean2000 macrumors 68000

    Santabean2000

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    #19
    I think we're on the same page. The problem is, folks who regularly run their MacBook from a charger typically don't give the battery enough 'exercise'.
     
  20. joeblow7777 macrumors 601

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    Sep 7, 2010
    #20
    Yes, I agree. People who ONLY use their laptop on A/C power for years and then need to rely on the battery for whatever reason might find that it's experienced more wear than they had anticipated. But similarly, people who ALWAYS rely on batter power may go through charge/discharge cycles and wear out the batter faster than they expect. The best approach is a balance, but I favour plugging in when possible.
     
  21. ct1211 macrumors 6502

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    Michigan
    #21
    You are correct, he is mistaken.
     
  22. motrek macrumors 68020

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    Sep 14, 2012
    #22
    The article you linked to and its source are talking about off-the-shelf li-ion cells and the most rudimentary charging mechanisms. This is what laptops used maybe 15 years ago and that's why their batteries would often go bad after 1-2 years.

    These days, charging is carefully managed to maximize battery longevity. Charge capacity is carefully monitored and charging is done at different rates (or not at all) to prevent damage to the battery. So leaving a laptop plugged in is no problem at all.

    Funny that you're telling me to do this, when I've actually done it, and I assume you haven't.

    I had a 2010 MBA for 4 years which I had plugged in almost all the time. When I sold it last year, it had over 90% of its original battery design capacity remaining and the battery was in good health.

    I now have a 2014 MBA which I leave plugged in almost all the time. The battery is 10 months old and has 102% of its design capacity.

    Where's your evidence?
     
  23. motrek macrumors 68020

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    Sep 14, 2012
    #23
    Also I should mention that I used this laptop as my home theater computer for almost a year. I would use it to stream Flash/Silverlight video for an hour or two every day. Because it was the Core 2 model, this really stressed the machine out and the CPU temperature was often over 90C. And the lid was closed the whole time. And it was plugged into the wall obviously.

    According to you, this should be the worst possible thing for the laptop. And yet the battery was still in almost-new condition after 4 years.
     
  24. Santabean2000, Apr 11, 2015
    Last edited: Apr 11, 2015

    Santabean2000 macrumors 68000

    Santabean2000

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    Nov 20, 2007
    #24
    "Desktop Mode monitors the charge status of the laptop battery, and if it spends most of the time at 100 percent charge while connected to the power adapter, Desktop Mode will automatically adjust the charge levels of the battery. The adjustments include regularly allowing the battery to discharge or drain, even while plugged in. The benefits help slow the reduction of charge capacity over time and may even decrease the need to purchase a replacement battery during the life of your laptop."

    It's just software doing what I'm suggesting. Guess we're both right. And wrong.

    Guess computer makers have to take more responsibility for general consumers who don't know better. [Hey, and I'm all for it; less broken pieces I have to sweep up]
     
  25. motrek macrumors 68020

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    #25
    I have no idea what you're quoting and I don't know what I said that you still think is wrong.

    Designing hardware/software/firmware that prevents overcharging is simply common sense. It has nothing to do with protecting irresponsible or uninformed consumers.
     

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