Keeping battery always plugged in when playing?

Discussion in 'MacBook Pro' started by Bilalo, Oct 31, 2013.

  1. Bilalo macrumors 6502

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    Aug 17, 2012
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    Oxford, England
    #1
    Hello

    Usually on my previous windows laptops battery is weak so i always keep in my charger for max graphics and brightness etc... With the mbp the battery is better, i can play 1-2 games without the battery but then again i put reduced graphics and so on, is it ok if I always keep it plugged in or does that ruin the battery for the mbp? Will it shorten its life or ruin it or make it last less or anything like that? What do you recommend I do? Just play until it says put in battery and then put it back?:confused:
     
  2. tmoerel macrumors 6502

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    Jan 24, 2008
    #2
    The biggest misconception about Lithium-Polymer batteries is that keeping them on the charger is bad.
    The opposite is actually true. The more you keep them charged and on the charger, the longer they last. The batteries in your Mac have a limited number of charge cycles so keeping them charged and topped up saves your battery's life.
     
  3. Love4ndpeace macrumors newbie

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    Aug 5, 2013
    #3
    unplug it once a week and drain it until less than 20% and plug it back. that's what I do. 8 months with 63 cycle my battery health is at 99.6%
     
  4. tmoerel macrumors 6502

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    Jan 24, 2008
    #4
    Sorry.....but this is wrong advice. This was true 10 years ago perhaps....but modern batteries have no memory effect and only wear out quicker when discharged.

    I am talking from experience as in my job I rely heavily on Lithium-Polymer batteries as used in macs.

    Somehow this old wives tale about discharging doesnt want to go away.
     
  5. Love4ndpeace macrumors newbie

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    #5
    well I provided solution based on concrete information based on my usage. myth or not is anyone's guess. thread starter may choose either options.

    and I guess it is more convincing if the source comes from apple itself no?
    http://www.apple.com/batteries/notebooks.html
     
  6. Bilalo thread starter macrumors 6502

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    #6
    You sure about that? I heard battery lasts less if I keep it plugged in. You mind finding me a source to make sure since its the first time I hear this from anyone.
     
  7. GGJstudios, Oct 31, 2013
    Last edited: Oct 31, 2013

    GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #7
    It's fine to leave it plugged in when playing. Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug any time you need to, regardless of the charged percentage, and you never need to completely drain your battery. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.
    That is not true. leaving plugged in too much will shorten the life, as the battery needs to be exercised to stay healthy. Batteries have a limited lifespan, regardless of the number of cycles. A battery can die from too few cycles faster than it can die from too many. Batteries do not "have a limited number of charge cycles"; they have a limited lifespan, even if unused.
    There is no need to drain the battery to any certain percentage.

    The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
     
  8. Alexjones macrumors 6502

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    May 28, 2010
    #8
    Leo Laporte, The tech guy will back you up on this. You are correct. Great advice.
     
  9. J4B3 macrumors regular

    J4B3

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    #9
    That's not exactly correct either. According to this article in Wired (http://www.wired.com/gadgetlab/2013/09/laptop-battery/), the only sure-fire method to prolong battery health is a charge to 80% and a discharge to 40%. However, the article concedes that this is entirely impractical and manufactures should implement a "smart" charging solution. Many PC makers already have a "smart" charge option; my Lenovo has an option to charge the battery to only 60% and disconnect the A/C current. But for practicality I simply leave my Macbook Pro connected 90% of the time and it has only resulted in a <10% decrease in capacity over three years.
     
  10. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #10
    Don't believe everything you read from BatteryUniversity.com, as their generic information does not include the proprietary charging technology used by Apple in its notebook batteries. You do not need to charge or discharge to any certain percentage to keep the battery healthy.
     
  11. zOlid macrumors regular

    zOlid

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    Jun 13, 2013
    #11
    Best is to keep between 50-80%.
    I really wish Apple would release a tool to keep the battery at 80%.
    I had that on my Sony Vaio 15s.
    And many other laptops also have it.

    But for your sake, just keep it plugged. Let it work once a month at least.
    And by that i don't mean to drain it fully, but to let it work to 50% and lower.

    There are 1000 different theories and articles about how to treat your batteries.
    And they are mostly the same, but have some different tips.
    Its hard to know what is absolutely best, but keep it plugged all the time if you want to, and let it work at least once a month. This tip is in most of the guides.

    What you really should avoid tho, is to fully drain it.
     
  12. GGJstudios macrumors Westmere

    GGJstudios

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    #12
    It is not necessary to keep the charge percentage in any particular range. Just use it as needed.
    Many people claim the "once a month" rule, but it has no basis in fact. Apple does not recommend leaving a notebook plugged in all the time and only using the battery once a month. You'll get much better results running on battery power for a few hours every few days, if you leave it plugged in most of the time.
    That's because too many people make it up as they go along, rather than follow Apple's own recommendations. Read the Battery FAQ posted earlier for information from Apple, who knows better than any user what is best for the notebooks they manufacture.
     
  13. zOlid macrumors regular

    zOlid

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    #13
    The tips about lithium batteries applies to all manufacturers.
    Apple don't have some special battery tech others don't have.
    And the 50-80% rule you can read about in many articles, and I even heard it mentioned on discovery when they had a program about lithium batteries.

    And like i said, if you want to keep it plugged, do so. But let it work every now and then, if you want to do it every few days thats totally fine, but you should AT LEAST do it once a month, but don't let it fully drain.
     
  14. GGJstudios macrumors Westmere

    GGJstudios

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    #14
    Yes, they do. Read the documentation. It's not just about the battery itself. The charging system involves the battery, the MagSafe adapter and the logic board. All of these components are not present in the same configuration in all notebooks.
     
  15. zOlid macrumors regular

    zOlid

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    #15
    Yes that is true, but lithium batteries are lithium batteries.
    In other words they work and last best when they are held between 50-80%.
    But its not practical to remove your charger to keep that setting, and thats why you should let the battery work every now and then.
    Better to do it every couple of days, but at least every month.

    This is true for ALL lithium batteries, and its true for Apples also.
    And its also what Apple recommends in their article about batteries.
    They also recommend to keep your battery at 50% for long storage, and that has to do with the 50-80% "optimal rule".
     
  16. GGJstudios macrumors Westmere

    GGJstudios

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    #16
    The 50% recommendation is for storage for 6 months or more. It has nothing to do with batteries in regular use.
    There is no "optimum" percentage. Too many people are making up nonsense as they go, misleading those who are looking for useful information. The best use is to forget about the percentages and just use the Mac, running on a natural mix of AC power and battery.
     
  17. nateo200 macrumors 68030

    nateo200

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    Northern District NY
    #17
    I wish their was a way to select "AC Power only" where it doesn't charge the battery, and not just after 94%~ maybe after 50% or anytime really...seams the charging system would be smart enough if Apple wanted to include it in an update but its so low level I doubt someone could make a custom app like gfxCardStatus or SMCfanControl.
     
  18. GGJstudios macrumors Westmere

    GGJstudios

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    #18
    If you fully charge the battery, it will run on AC power only, unless power demands require drawing power from both the battery and AC power, as in cases of extreme gaming.
     
  19. nateo200 macrumors 68030

    nateo200

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    #19
    Well aware. I've seen the battery tapped as well but what I want is AC power only regardless of battery level because if I step away for one second unplugged while I'm editing a video with 3 thunderbolt devices and all the USB ports it will drop below 90% in a matter of minutes and it doesnt make sense to apply a charge even at 88%
     
  20. GGJstudios macrumors Westmere

    GGJstudios

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    #20
    I understand, but as long as you're not doing that constantly, recharging from 88% ... or any percentage... isn't going to hurt anything.
     
  21. mykelala01 macrumors 6502

    mykelala01

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    #21
    Not actually Leo Laporte... The more intelligent man behind Leo Laporte, who teaches him stuff, "Steve Gibson." Steve Gibson actually, have it explain in one of his Security Now podcast, explaining Lithium battery are happy to be charge and keep the Ion moving.
     
  22. zOlid macrumors regular

    zOlid

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    Jun 13, 2013
    #22
    If this was true, why are the manufacturers of Lithium batteries saying 50-80%?
    And why are many other brands then apple mention those exact numbers, and even have software that locks the charging to no more then "a number between those".
    If there really where no substance to this claim at all, there wouldn't be these kind of settings, since people for sure rather have 100% of their battery when they need it.


    http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries


    "Commercial chargers do not allow changing the charge voltage limit. Adding this feature would have advantages, especially for laptops as a means to prolong battery life. When running on extended AC mode, the user could select the “long life” mode and the battery would charge to 4.00V/cell for a standby capacity of about 70 percent. Before traveling, the user would apply the “full charge mode” to bring the charge to 100%. Some laptop manufacturers may offer this feature but often only computer geeks discover them."




    http://lancair.net/lists/lml/Message/56976-02-B/Li-Ion%20Battery%20Life.pdf

    "Using partial-discharge cycles can
    greatly increase cycle life, and charging to less than 100%
    capacity can increase battery life even further"

    "Unfortunately, charging and maintaining the battery near these levers (100%) shortens battery life. One solution is to select a lower float voltage, which prohibits the battery from achieving 100% charge.
    ...Reducing the float voltage by 100 mV will reduce capacity by approximately 15% but can double the cycle life."

    "the battery is only charged to approximately 85% of capacity, which is an important factor in battery life."

    (a charger) "can provide a longer battery life by selecting the correct charge-current level at which to en the charge cycle.
    A C/10 termination level will only bring the battery
    up to about 92% capacity, but there will be an increase in
    cycle life. A C/5 termination level can double the cycle life
    although the battery charge capacity drops even further to
    approximately 85%"

    "For maximum run-time, the charger must
    charge the battery to 100% capacity. This places the battery
    voltage near the manufacturer’s recommended float voltage,
    which is typically 4.2 V ±1%. Unfortunately, charging and
    maintaining the battery near these levels shortens battery
    life."

    "Avoid charging to 100% capacity. Selecting a lower float voltage can do this. Reducing the float voltage will increase cycle life and service life at the expense of reduced battery capacity. A 100-mV to 300-mV drop in float voltage can increase cycle life from two to five times or more."



    There are hundreds of these articles on the net. And many of them are really scientific.
    And that's why many brands have software to lock charging to less then 100%, usually between 50-80%.

    If there where no truth to this, there wouldn't be such software, and it most definitely would not be these studies about the gain you can have from it...
     
  23. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #23
    As I stated earlier, generic sites like BatteryUniversity are not as reliable sources of information about Apple notebook batteries and Apple's proprietary charging system. You can do whatever you want, but the most reliable information about Apple notebook batteries is Apple itself. I would not recommend anyone treat their battery any different than Apple recommends. BatteryUniversity and other manufacturers did not design Apple's charging system and are not responsible to honor the warranty or AppleCare, should a battery not perform as expected. Apple has a vested interest in making sure its users get the most from their batteries, to minimize warranty claims.
     
  24. rMBP2013 macrumors member

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    Oct 22, 2013
    Location:
    Sydney
    #24
    So what exactly is your advise?

    Keep it plugged in all the time? :confused:
     
  25. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #25
    Not at all! You shouldn't leave it plugged in all the time, but you don't have to drain it to any particular percentage, as long as you run on battery a few hours every few days. The battery needs to be exercised regularly to stay healthy, but there is no need to get hung up on specific percentages. Read post #7 and the link in that post for more information.
     

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