MBP as desktop, maintaining battery life

Discussion in 'MacBook Pro' started by FaultyGluestick, Mar 4, 2009.

  1. FaultyGluestick macrumors member

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    #1
    Hi, I'm using my macbook pro mostly as a desktop plugged into a monitor, but I occasionally bring it to school. After killing my first battery, I've finally learned to not keep it plugged and charged 24/7, yeah real stupid. If I infrequently use the battery, should I take it out when using it as a desktop? How often should I actually use the battery to keep it from going "stale"? I just busted out what little money I had for a new one, so I want to keep it alive for as long as possible. Thanks! :)
     
  2. ceezy3000 macrumors 6502

    ceezy3000

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    #2
    waste the battery at least three times a week
     
  3. GGJstudios macrumors Westmere

    GGJstudios

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    #3
    Don't run it without the battery in it. If you're using it plugged in most of the time, every 2 or 3 days, unplug it and let the battery drain down to about half, then plug it back in. Also, be sure to calibrate it at least once a month, as Apple recommends.
    That is absolutely NOT recommended and will shorten your battery life!

    http://www.apple.com/batteries/notebooks.html
     
  4. Mr. Giver '94 macrumors 68000

    Mr. Giver '94

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    #4
    Hmmmm I thought that all Apple batteries could be plugged in as long as you want. They charge based on cycles i.e. they won't continue to charge/excite the ions after reaching a full charge.

    Am I wrong? :confused:
     
  5. alphaod macrumors Core

    alphaod

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    #5
    I recently starting using my MBP as a desktop; bad idea—battery is dying.
     
  6. GGJstudios macrumors Westmere

    GGJstudios

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    #6
    From: http://www.apple.com/batteries/notebooks.html
     
  7. FaultyGluestick thread starter macrumors member

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    #7
    I'm proof that that doesn't work :p Thanks guys!
     
  8. Mr. Giver '94 macrumors 68000

    Mr. Giver '94

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    #8
    Ahh I see. Since the OP brings it to school it should be fine though right.


    OP maybe you can alternate using it with and without the monitor. You can use it in other rooms of your house or take it to a Starbucks or something. ;)
     
  9. GGJstudios macrumors Westmere

    GGJstudios

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    #9
    As long as you unplug and run down to around 50% every 2 or 3 days, it should be fine using it as a desktop. Mine's at the desk 98% of the time.
     
  10. samh004 macrumors 68020

    samh004

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    #10
    If your battery is at 95% - 100% and you plug it in, it wont start charging, it'll just draw power. If your battery is below 95% and you plug it in, it'll start recharging up to 100% at which point it'll stop.
     
  11. mattyb240 macrumors 6502a

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    May 11, 2008
    #11
    I have left mine plugged in since september, an have put 60 cycles on it and have 99% battery health. My friend who is a mac specialist and her friends who are geniuses say it does no harm to leave i plugged in as it powers straight off the power supply on not through the battery. As long as you calibrate once a month or more you should be fine. While I found this hard to believe I still get 4+ hours of battery life.
     
  12. ThirteenXIII macrumors 6502a

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    #12
    ive been using a 15" unibody for almost two months now and just 1 cycle charge and still 100% health, a buddy has had one longer with only 2 or 3 cycles, same system.

    i keep it plugged in all the time and use it with a external display, once the indicator shows below 99% charge, i unplug it and let it drain to about 92-95% and then it goes all the way back up to 100% give it room to get the charge back.


    once you drain to 50% and then back up and then back down to 50% that will complete 1 cycle
     
  13. Abstract macrumors Penryn

    Abstract

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    #13
    You're actually sort of right, as is mattyb240 and samh004. You can plug in your laptop for as long as you want, except every 3 or 4 weeks you should use it down to zero. This isn't an Apple-related thing. This is related to all lithium ion batteries (also used in mobile phones), so proper use of the battery will help you with any device. ;) Apple's charging method reduces the number of battery charge cycles using the method described by samh004 in an earlier post. Apple only charges your battery when it's less than 97% (although they may have changed this value). That's why when your battery is at 98% (for example), it won't charge back to 100%.

    (However, this may not be true of the new lithium-polymer battery used by Apple in the 17" MBP, since it's not a typical lithium-ion.)

    Actually, the best thing to do to preserve your battery is to keep it at 40% charge all the time, and keep it stored in a cold room. You can even pull out the battery and keep it in a somewhat cool place. However, keeping its charge at 40% isn't practical, and so keeping it inside your laptop, and draining your battery every few weeks should be absolutely fine. You don't even need to drain it all the way. However, drain it from 100% to 0% every 4-6 weeks and recharge it to full again. You should do this to recalibrate, so that your system knows what a 100% full charge still looks like, and what empty looks like. It's like your system forgets the start and end points, so you need to reteach it.
     
  14. emt1 macrumors 65816

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    #14
    Sorry, they're wrong. The power supply alone cannot supply an adequate amount of power to run the laptop. The battery power is also utilized while the computer is plugged in. If you remove the battery while the laptop is plugged in, the processor speed drops drastically to compensate for the loss of power.
     
  15. kastenbrust macrumors 68030

    kastenbrust

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    #15
    Thats true. Apple even says so on its own site. I think one core gets deactivated on the processor.
     
  16. Runt888 macrumors 6502a

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    #16
    Close, but not entirely correct. The power supply cannot guarantee an adequate amount of power under all possible circumstances, so it underclocks the processor to ensure no damage occurs if more power is needed than can be delivered. However, the power supply is able to run the computer and charge the battery under normal conditions.
     
  17. MagicWok macrumors 6502a

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    #17
    Care to show a link to the Apple site where it says this? Would be interested to read this for myself actually...
     
  18. J.Genius macrumors newbie

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    Mar 5, 2009
    #18
    this is true, apple does recommend the battery be installed in the unit when it is in operation. the laptop will have degraded performance if run without the battery installed.

    http://forums.macrumors.com/showthread.php?t=273551

    i cant cite a apple article, but i can tell you from apple portable training they let this be known.

    ;)
     
  19. Runt888 macrumors 6502a

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    #19
    http://support.apple.com/kb/HT2332

    And logic would dictate that since the battery can be charged while using the laptop, the power supply can obviously provide enough power to do both under normal conditions.
     
  20. Abstract macrumors Penryn

    Abstract

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    #20
    It's interesting.

    I have a question though. How do we use the laptop AND charge the battery (or at least keep it topped up so that it doesn't drop to 0%) if the AC power supply can't supply enough power to run the laptop even WITHOUT the battery? :confused:
     
  21. Runt888 macrumors 6502a

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    #21
    Hence my previous posts...
     
  22. kastenbrust macrumors 68030

    kastenbrust

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    #22
    Thats probably why Apple laptops take so long to charge.
     
  23. Abstract macrumors Penryn

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    #23
    But according to that post, the battery's capacity would actually drop even if the laptop was plugged into the AC power outlet. If the AC (supposedly) doesn't provide enough power to even keep the laptop running without the battery, so what's charging the battery? (And don't say "the battery." :p)

    In fact, if that were true, the battery's charge would diminish after several hours of not being unplugged from the power outlet, even if the laptop is turned off.
     
  24. Runt888 macrumors 6502a

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    #24
    If you're talking about the link I posted, it doesn't say the AC adapter doesn't provide enough power. It says the AC adapter doesn't always guarantee enough power under all conditions. The amount of power your laptop needs varies depending usage. Under certain conditions, power requirements can spike, resulting in a need for more power than the AC adapter can provide alone. However, under normal conditions the AC adapter can fully power the laptop, with some left over to charge the battery.
     
  25. MagicWok macrumors 6502a

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    #25
    Cheers. ;)

    Basically Apple is covering themselves a little. They're not saying the adaptor can't power the laptop by itself, of course it can, they're just underclocking incase the power supply you plug into doesn't have enough juice to run the laptop. As would be the case when you take laptops on to planes and plug in using empower ports. Airlines specifically state in that situation, the in-seat port provides enough power to run the laptop, but not charge.
     

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