MacBook Pro Retina - How much power lost when off?

Discussion in 'MacBook Pro' started by humfer, Sep 21, 2014.

  1. humfer macrumors newbie

    Joined:
    Sep 21, 2014
    #1
    Could really do with your user experience. I'm losing over 100mAh when switched OFF. Different Apple people tell me this is ok / nok and don't know where to turn next.
     
  2. humfer thread starter macrumors newbie

    Joined:
    Sep 21, 2014
    #2
    Anyone? If you have a MacBook pro what do you notice on your machine? I did some tests over the weekend in sleep mode and initially it only dropped 25mAh over 24 hours but then dropped 200mAh over the next 24 hours. So completely random and don't know what to do
     
  3. Yakibomb macrumors 6502

    Yakibomb

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    May 13, 2014
    Location:
    Cape Town
    #3
    Under energy settings do you have 'Power Nap' enabled? This could explain your power loss as your laptop would still be checking for emails and iCloud updates whilst in sleep mode
     
  4. humfer thread starter macrumors newbie

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    Sep 21, 2014
    #4
    Thanks for the reply. I'll check tomorrow when I next fire it up. However what about when the machine is completely turned off? How much power should it use? What's your machine do?
     
  5. Yakibomb macrumors 6502

    Yakibomb

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    May 13, 2014
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    Cape Town
    #5
    To be perfectly honest I have no idea whats normal or not. I'll check how much charge I loose tonight and post tomorrow
     
  6. simonsi macrumors 601

    simonsi

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    Jan 3, 2014
    Location:
    Auckland
    #6
    Measuring battery capacity in mAh is subject to error every time a reading is taken by anything at all. More accurate is measuring charge and discharge. While off this can't be done so you get an estimate and that will vary.

    Even when off, batteries of all kinds in all devices have a self-discharge rate, I'd expect of the order of 1-2% per day.
     
  7. konradsa macrumors regular

    Joined:
    Aug 25, 2014
    #7
    I noticed too that the discharge amount seems to be somewhat random. Sometimes it sleeps for a day and barely loses anything, other times it seems to have shed 5% in 3 hours.

    Honestly, I chalked it off to variations in measuring the remaining capacity of the battery. I guess the measurement is not 100% precise, so you have some variations in there.
     
  8. humfer thread starter macrumors newbie

    Joined:
    Sep 21, 2014
    #8
    Have checked and power nap not selected so that's not to blame. Did you manage to find time to check how much your battery lost whilst switched off overnight? Mine has lost 400mAh between switched off Sunday night and turned back on Wednesday night. If it's normal then I'll just put up / forget about it. if not then store I bought it from in the UK has agreed to send it away to authorised Apple repairers for them to investigate further
     
  9. simonsi macrumors 601

    simonsi

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    Jan 3, 2014
    Location:
    Auckland
    #9
    So the battery would flatten in around 45 days at that rate. Sounds fine to me.

    Bear in mind it is never truly off as even the power put-on is a soft switch so the logic board is minimally powered in order to recognize the button being pressed to power on....
     
  10. duervo macrumors 68000

    duervo

    Joined:
    Feb 5, 2011
    #10
    "Some" discharge, when the system is completely off, is normal. As long as a battery is plugged in to the logic board (not to AC power) there will always be discharge, even when the system is completely powered off (i.e.: system clock.)

    How much discharge is normal, I couldn't say for certain, but I wouldn't really worry too much about it, unless it went completely dead in a couple weeks or less.
     
  11. konradsa, Sep 25, 2014
    Last edited: Sep 25, 2014

    konradsa macrumors regular

    Joined:
    Aug 25, 2014
    #11
    400 mAh in 3 days, that's like 2% a day. Sounds very normal to me, actually pretty good.

    I just checked mine over night: It lost 143 mAh already just in the 3 hours sleeping after I put it down. Then after three hours it goes into hibernation, it lost another 12 mAh in the 5 hours it was hibernating. So if you extrapolate that to 3 days, I am sure I would have ended up with something similar. I am actually surprised how much it loses during the first 3 hours of sleep.

    Keep in min that there are fluctuations also due to the mAh measurements not being very reliable, it gets skewed by temperature, load, and other factors.
     
  12. snaky69 macrumors 603

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    Mar 14, 2008
    #12
    Can't say, I don't remember ever shutting down any Mac I've owned except for desktops.
     
  13. humfer thread starter macrumors newbie

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    Sep 21, 2014
    #13
    Thanks for the replys. Maybe I have been worrying about nothing then. As only just coming to end of 1st year of a 3 year warranty think I'll hold of sending it away to be fixed, where based on your inputs they wouldn't find anything wrong/change anything. Plus as how IOS8 has bought my iPad to its knees I need something else to run safari on!
     
  14. Alexjones macrumors 6502

    Joined:
    May 28, 2010
    #14
    I would plug it in after 1 1/2 - 2 days of being powered off. You will waste a battery cycle if you have it unplugged for more than 30 - 48 hours even if it is fully shut down.
     
  15. Master D macrumors newbie

    Joined:
    Dec 3, 2013
    #15
    I've noticed discharge in sleep mode when items are plugged into the USB ports...
     

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