Do you stay plugged in after hitting 100% charged?

Discussion in 'MacBook' started by Saurus504, Aug 5, 2015.

  1. Saurus504 macrumors member

    Joined:
    Jul 14, 2015
    #1
    I always hear that degrades the battery faster if you just always stay plugged in but don't really know for sure. I always try to charge to 100%, unplug, let it go all the way down to at least about <5% and then plug back in. Does any of that really matter?

    Rolling with the new 12' macbook btw.
     
  2. iZac, Aug 5, 2015
    Last edited: Aug 5, 2015

    iZac macrumors 68000

    iZac

    Joined:
    Apr 28, 2003
    Location:
    Shanghai
    #2
    I ended up using my 2011 MBA as a TV media server for about two years. It basically ran 24/7, I rarely unplugged it or turned it off. (Yes I know this is laptop abuse!)

    Over those two years it had managed 260 loadcycles and was down to 54% health according to coconut battery. I did get the battery replaced for free by Apple though, since they considered it faulty that it could go through so few loadcycles and be nearly half capacity (I didn't mention my usage pattern)

    So yup, although mine is an extreme case, leaving it plugged in can damage the battery. Run it on battery and don't [SNIP] worry too much.
     
  3. ahostmadsen macrumors 6502a

    Joined:
    Dec 28, 2009
    #3
    Modern batteries don't like to be drained. Better to discharge a little and then recharge. Check Apple's guidelines on batteries. I read that keeping it between 40% and 80% is optimum, but I'm not sure that is verified.
     
  4. iZac, Aug 5, 2015
    Last edited: Aug 5, 2015

    iZac macrumors 68000

    iZac

    Joined:
    Apr 28, 2003
    Location:
    Shanghai
    #4
    Apologies, I don't mean to cause a rift in best practice for batteries. It could rage for days :p

    The main take-away from my post was not to run it plugged in all the time like I did.

    Apples replacement program is now considerably better though, so the OP shouldn't worry too much about abusing their machine.
     
  5. pastrychef macrumors 601

    pastrychef

    Joined:
    Sep 15, 2006
    Location:
    New York City, NY
    #5
    I also recommend not keeping it plugged in all the time. I had my old MacBook plugged in all the time and I think it was the cause of its battery swelling up and needing replacement. I now use an app named FruitJuice to help remind me to unplug it and use the battery once in a while.
     
  6. mattopotamus macrumors G4

    mattopotamus

    Joined:
    Jun 12, 2012
    #6
    There is nothing wrong with leaving it plugged in 24/7. If fact, it will actually preserve your battery health. Use it plugged in as much as you can.
     
  7. zhenya macrumors 603

    zhenya

    Joined:
    Jan 6, 2005
    #7
    Keeping it plugged in 24/7/365 is a lot different than keeping it plugged in overnight or during the day while you use it at your desk. There are two states that are non-ideal for modern battery tech - deep discharge and full charge, with deep discharge having the potential to do more damage in a short timespan. 40-80% is the ideal, but in practice, just use the thing, try to avoid constant deep discharge below 10% or so, and you'll most likely be fine. Charging it fully or mostly full, then discharging to 40-50% before recharging is probably the best scenario that is relatively practical for most people.
     
  8. tbirdparis macrumors 6502

    Joined:
    May 30, 2015
    #8
    I'm pretty sure I read an Apple document about the best practice for the battery type used in the new MacBook but I can't find a link right now. Anyway from memory it said pretty much what Zhenya says: Ideally you should avoid ever letting it run down to empty, and you should avoid keeping at 100% all the time too. The ideal range seems to be to always hover around half full. In practice though, I suppose a good strategy might be to charge it fully, let it run down to 50% or lower, charge again (while still using it if you want), repeat. Depending on how you get about your day, this might mean taking a charger around with you. But if like me you find that you get home and it's still not anywhere below 70%, I have plenty of margin left over to then get it to charge back up again in the evening.
     
  9. dusk007 macrumors 68040

    dusk007

    Joined:
    Dec 5, 2009
    #9
    Running the battery down and recharging then running it down again is the fastest way to run through all the cycles the battery is worth and killing it. Unless you pick up your notebook rarely.
    Usually just leave it plugged in and occasionally once a week or every fortnight run it on battery for 20-50% then recharge. Only NickelKadmium batteries like to be discharged fully, Lithium actually don't like but are perfectly fine with smaller discharges. 5 times to 80% and back to full is still only a single cycle.

    In theory all the things that hurt battery life are things you can do nothing about, so it is really not worth it to worry about it. I.e heat, if you don't use your notebook so it does not heat up and store it in a cold dry place the battery will prefer that, but you bought it to use it so do it. Heat makes more difference then your charging routine and you cannot do anything about it, other than not letting it lie around in direct sunlight to turn it into a stove.
     
  10. tbirdparis macrumors 6502

    Joined:
    May 30, 2015
    #10
    Indeed, I think the type of batteries used nowadays are quite different from the early days. It's much more the case now that you can just use your device pretty flexibly, charge it when you need to or when you get a chance, and just get on with it. Of course it's always good to know what to avoid doing that might significantly shorten its life but generally the situation is a lot more chill than it used to be.
     
  11. Saurus504 thread starter macrumors member

    Joined:
    Jul 14, 2015
    #11
    Thanks for all the great info guys. It will most likely sit on my desk about 80% of the time so while it does that I'll probably just keep it plugged in. I'll unplug it overnight though.
     
  12. throAU macrumors 601

    throAU

    Joined:
    Feb 13, 2012
    Location:
    Perth, Western Australia
    #12
    My early 2011 15" has spent most of its life on AC, has a couple of hundred cycles and 88-90% health on the battery.

    My ex had her 2010 11" Air 1 year longer (2010 model) and it was down to 50% health 6 months ago - and she rarely ran on AC.

    2c: use the machine on battery if you need it, or on AC if you're at a desk. Stress less about it, Apple guarantee the battery for 80% plus after 3 years now anyway i think.
     
  13. mattopotamus macrumors G4

    mattopotamus

    Joined:
    Jun 12, 2012
    #13
    That is what I do. I use it in clamshell mode mon-friday and at night take it home, uncharged all night. On the weekends I also leave it unplugged and use it here and there.
     
  14. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #14
    That is not correct. You can leave it plugged in all you want and it won't hurt anything. By unplugging needlessly and running it down you are consuming battery cycles for no reason.

    Look over these two official links on batteries from Apple.

    http://support.apple.com/kb/HT1446

    http://www.apple.com/batteries/
     
  15. ZipZap macrumors 601

    Joined:
    Dec 14, 2007
    #15
    My rMBP was plugged in for the better part of 3 years. 6 Cycles when I sold it. No swelling, no issues at all. Apple's software does not maintain 100% charge. Ever. It is safe to leave it plugged in despite what has been posted.
     
  16. NavySEAL6 macrumors 6502a

    Joined:
    Dec 13, 2006
    #16
    That's exactly what I do. I use it plugged in at my desk and leave it in sleep overnight unplugged. You should let the battery drain once a month and fully recharge (look up how to calibrate your models battery).

    I have also heard keeping the battery between 20-80 is optimal but not necessary. Not sure if this is true but food for thought
     
  17. facrat macrumors member

    Joined:
    May 15, 2015
    #17
    No: "If your portable Mac has a built-in battery, you don’t need to calibrate the battery."
    https://support.apple.com/kb/PH14087
     
  18. joeblow7777, Aug 6, 2015
    Last edited: Aug 6, 2015

    joeblow7777 macrumors 68040

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    Sep 7, 2010
    #18
    Old battery habits die hard. People still perpetuate charging/discharging habits based on old nickle-cadmium batteries even though lithium ion batteries have been the standard for many years now.

    Modern batteries and the devices that use them do not allow for over charging, so keeping the device plugged in while fully charged does no harm. Nor do they have a "memory effect", so they can be charged whenever you want for as long or as short a time as you want.

    This is the optimal charge range to keep your battery in, in order to minimize battery wear. But I personally don't think that the potential gains are worth the inconvenience. What Apple should do (and Microsoft should do in Windows) is build in a way for the user, through the OS, to tell the battery when to stop charging. That way, those who work at a power socket most of the time could keep their computer plugged in but the battery kept in the sweet spot. I actually used to have a Samsung netbook that offered such a "Battery Life Extender" feature, that made it so that the battery stopped charging at 80%.
     
  19. Dayv macrumors 6502

    Joined:
    Aug 18, 2009
    #19
    My philosophy is to not worry about the battery too much in general. I unplug it when I'm using it much of the time because I use it around the house or in an easy chair more than at a desk. I plug it in when it's convenient to do so, and leave it plugged in until it's not convenient.

    If I need to replace the battery in three years or more, that's fine. This usage pattern gave me over four years of acceptable battery life on my previous MBP, after which I still used it for two more years with far more frequent recharging.

    It's a modern battery, the system manages it fairly well, it's not worth stressing out about.
     
  20. ZipZap macrumors 601

    Joined:
    Dec 14, 2007
    #20
    TOTALLY, not necessary. I kept mine plugged in for 3 years. 6 battery cycles on the rMBP after 3 years.
     
  21. diesel macrumors 6502a

    Joined:
    Aug 3, 2007
    #21
    Why overthink this??? If you don't need to run on battery keep it plugged in. If you need to use it on battery then go for it. No need to plan to do xyz and then abc and such and such. Keep it simple and use your machine as you need to.
     
  22. NavySEAL6 macrumors 6502a

    Joined:
    Dec 13, 2006
    #22
    How's your battery life? Download coconut battery and check your battery health. I would be curious to see what it is
     

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