Best Battery Life when Plugged or Not Plugged?

Discussion in 'MacBook Pro' started by varchar, Oct 17, 2009.


AC Plugged in or Not?

Poll closed Oct 22, 2009.
  1. Plugged in

    6 vote(s)
  2. Un-plugged

    4 vote(s)
  1. varchar macrumors member

    Aug 9, 2008
    A daunting question is always on my mind. I use my MBP 15" (the new one), as my primary machine in my office. I sit by my best usually 10-12hrs a day working on it.

    I am trying to figure out what is best to do, keep the AC plugged in or have it un-plugged and only plug it in when the battery is drained (or less then 50%)? I have tried different experiments, plugged in, not-plugged and time is about the same for life of the battery. The true question is, how is is best to do it for the health of the battery.

    I was even thinking, maybe its just a good idea to get the new iMac (when it comes out) and use that as my primary... dunno...

  2. GGJstudios macrumors Westmere


    May 16, 2008
    There's no need for a poll on this. It's not up for a vote. Refer to Apple's information on notebook batteries. You should unplug and run on battery every few days, to keep electrons moving, and calibrate about once a month.
  3. ntrigue macrumors 68040


    Jul 30, 2007
    Best practice would be to maintain battery life between 20-80%. Your longevity will be affected if you always run on power.

    Either way be sure to calibrate every month.
  4. oculus42 macrumors 6502

    Dec 9, 2002
    My MBP's battery is near death after two years of mostly plugged in use. iStat Pro reports 151 cycles, 32% health. My last MBP spent more time unplugged and seemed to survive better, but I only had it for one year.

    If it's always on a desk, consider a desktop. You can either spend less or get more for the money.
  5. Captain Planet macrumors 6502a

    Captain Planet

    Mar 24, 2007
    Usually, I use it unplunged until maybe 5-10 % remaining.
  6. Richard1028 macrumors 68000

    Jan 8, 2009
    I'd venture to say that nobody's battery would maintain proper health if constant power were to be applied most of the time. Mine sure hasn't but I didn't figure this out until a few weeks ago.

    Now, at least once a day I make sure I'm running on battery only until about 20 minutes remaining. My battery health has gone from 85 to 95% (82 cycles) and it's still rising (I hope).
  7. ntrigue macrumors 68040


    Jul 30, 2007
    Ultimately, the replacement is between $60-115 so **** it...
  8. GGJstudios macrumors Westmere


    May 16, 2008
    Where are you getting those prices? Apple charges $179 to replace the battery on a 17" MBP and $129 for the 15" and 13".
  9. Rotator macrumors newbie

    Oct 6, 2009
    Look behind you!
    Probably 3rd party re-seller. I suggest you just get one directly from apple to ensure best quality.
  10. GGJstudios macrumors Westmere


    May 16, 2008
    I don't believe any 3rd parties sell the unibody battery. They have to be replaced by Apple to keep from voiding the warranty.

    Replacing the battery in MacBook Pro (Early 2009) and later
    I found the prices:

    Replacing the Battery in your MacBook Pro:
    Picture 1.jpg
  11. ntrigue macrumors 68040


    Jul 30, 2007
    When you NEED the replacement it will be much less expensive in three years.

    Plus, under $200, wonderful!

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