will it screw with the battery to leave it plugged in all night?

Discussion in 'MacBook Air' started by Openbook, Aug 4, 2011.

  1. Openbook macrumors newbie

    Joined:
    Jul 20, 2011
    #1
    so my battery is down to 3% and I just plugged it in, but am heading for bed soon, will it mess with the battery to leave it plugged in overnight. I know it seems foolish as I lead plenty of other stuff charging all night, such as my iPad, but it never hurts to ask,
     
  2. Intell macrumors P6

    Intell

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    #2
    No, it is perfectly fine for it to be plugged in overnight.
     
  3. Openbook thread starter macrumors newbie

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    Jul 20, 2011
    #3
    thanks, I know I am likely just being a bit paranoid
     
  4. alecgold macrumors 65816

    alecgold

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    #4
    No, my wife's is plugged in al its life and still fine!
     
  5. Intell macrumors P6

    Intell

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    #5
    It should be noted that having a laptop plugged in all its life is not good on the battery. In most cases it causes the battery to die prematurely.
     
  6. PaulWog Suspended

    Joined:
    Jun 28, 2011
    #6
    In that case the battery would keep draining to 95%, then charging back up to 100%, over and over again.

    Giving it "breathing room" and variation in its cycles is important for sure.

    Apple I think recommends if one is storing the computer/battery for lengthy periods of time, leaving it at approximately 50% charge is best. So if I were to leave mine off for say... a month (why would I have a laptop if I wasn't using it within a month?), I'd probably leave it at 60% to give it room to drain while being off and whatnot.

    @OP: I left my Air charging overnight. You can leave it charging all day too. It's best to let the battery run through at least one or two cycles a week though I'd say (if you're using the computer actively). Using it often where it would keep on dropping to 95% and charging back up to 100% would be bad (the battery doesn't charge until it hits 95% I think it is, so if you operate off the wall, you might lose 1% battery charge per unit of time that you would in sleep mode... so eventually it would hit 95% and charge up again on you even though you aren't operating it off of the battery).
     
  7. Intell macrumors P6

    Intell

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    #7
    No it doesn't. If you plug an Air, Dell thing, or HP thing in and leave it plugged in. The battery will never dip past 100%, unless the computer needs more power than the brick can provide. The act of not discharging will kill the lithium ion cells within the battery.
     
  8. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #8
    When the battery is fully charged, it stops charging, even if it's still plugged in. It will not overcharge. This should answer most, if not all, of your battery questions:
     
  9. PaulWog Suspended

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    Jun 28, 2011
    #9
    Uhhhh.... yes it will dip below 100%.

    Once your battery is charged, the laptop will run off of the wall power. The battery is left idle. An idle battery will discharge over time. Try leaving your computer off for a couple days and come back to it (leave it plugged into the wall the entire time so when you turn it on it isn't using battery life). Once you turn it on, you'll see you've lost 1-2% battery life.

    What happens is if you use your Air like a desktop, it will slowly discharge the battery down to 95%, then charge back up to 100%. This will happen over the period of a few days. It's not using the battery for power, but the battery simply is not 100% efficient in the way it keeps itself charged.
     
  10. Intell macrumors P6

    Intell

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    #10
    If your battery looses that much power over a few days then there is something wrong with it. None of mine loose that much that fast. Mine die at about 2% a month when they are not used. At that rate, the 95% charge ability of Macs won't be enough to keep the battery healthy. Even at the rate your's are draining, the battery still isn't cycled enough to prevent a premature death.
     
  11. Les Kern macrumors 68040

    Les Kern

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    #11
    this may sound smug, but i factor in buying a new battery over time, usually 2 years, and do whatever the hell I want to do. Having fewer things to worry about like a battery makes my life easier.
     
  12. PaulWog Suspended

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    Jun 28, 2011
    #12
    I'll do a more thorough test to see where I'm at. I'll also ask a couple other people to just get a general idea (I trust you aren't off on the rough numbers you gave me, but I'll just see).

    Guess it'll be good to see for myself if my battery discharges overly fast when turned off.
     
  13. Travisimo macrumors 6502a

    Joined:
    Dec 22, 2009
    #13
    ^^^ This. Sometimes we over-analyze things to death! Nothing lasts forever, but as long as you don't abuse it, it'll most likely last long enough until your next upgrade. If not, just get a new battery put in.... it'll be far less expensive than buying a new machine.
     
  14. LightOnAHill macrumors regular

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    Jun 26, 2010
    #14
    It is important to know that a li-ion battery will begin to have internal corrosion FASTER when it is above 95% capacity for a long period of time (overnight a lot, or sitting on a desk). This type of corrosion will not begin as quickly if you can keep the laptop at rest during the night at about 60% to 80% charge.

    I like to charge my laptop to about 85% at night before bed, then unplug it, turn it off, and let the whole thing rest. Then in the morning, I plug it in when I wake up, let it charge up to like 95%, then rock out the day, using the battery from here to there, and charge it back to about 85% at night.

    This allows for it to be at or around 100% without having to spend a lot of idle time sitting AT 100% or thereabouts.

    The things that taught me this was that I'm a flash-a-holic and I spend quite some time on candlepowerforums where I've learned a lot about li-ion and I have different li-ion batters of all sizes and configurations for lights and computers and other issues.

    It could take a year or two before you'd notice a difference leaving it charged at 100% all the time, but guaranteed you WILL notice a difference. I took really good care of my last thinkpad extended battery and it still gives me seven hours and it's 3.5 years old. My best friend bought the same laptop and battery at the same time, and never considered paying attention to this type of stuff, and her battery will only give about 3 hours of work in the same machine -- this is because of the internal corrosion that has been accelerated due to the battery being at full charge.


    I believe that Apple will replace li-ion batteries when they get old or corroded or what-not, but I'd prefer to try to get some life out of my batteries.

    If anybody could chime in on a program that would let us stop the charging at like 88%, that would make my day, so I could jus leave it plugged in, but not have it sitting hot at 100% all the time.

    My .02. :)
     
  15. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #15
    You're assuming that the lithium polymer batteries used in Mac portables are the same as all other li-ion batteries. They're not. For one thing, you haven't factored in the smart battery technology incorporated into Apple batteries. You can't apply generic information across the board to the specific batteries used in Apple notebooks. For that reason, it's best to follow Apple's recommendations on battery care, since they know exactly what's best for their particular battery technology.
     
  16. YEEZY macrumors member

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    Jul 29, 2011
    #16
    But what would be ideal for the battery? Just leaving it unplugged and charging to almost maximum?
     
  17. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #17
    The best approach is to run on battery when you need to and plug in whenever you can. Just don't run on AC power all the time, as your battery needs to be exercised to stay healthy. Read the Battery FAQ I posted in post #8.
     
  18. YEEZY macrumors member

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    Jul 29, 2011
    #18
    Great! Thank you, I'll be sure to do that now because I always felt that leaving the computer plugged in the whole time would be detrimental to its overall health.
     
  19. Mlrollin91 macrumors G4

    Mlrollin91

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    Nov 20, 2008
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    Ventura County
    #19
    All my laptops have lost 1-2% every day or so after being plugged in at 100%. My 2007 MacBook, 2009 MacBook Pro and my 2011 MacBook Air. For it to drop it 95% in order for it to recharge on its own takes about 1 week of being plugged in and idling, but it will still do it.
     

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