iMac 27" Battery / On Location Power?

Discussion in 'iMac' started by M3Jedi77, May 21, 2018.

  1. M3Jedi77 macrumors member

    Jun 30, 2007
  2. MandiMac macrumors 6502a

    Feb 25, 2012
    Well, if the product indeed does output up to 200 W you should be safe. My iMac needs around 60 W in idle state.

    But then again, how long do these 42000 mAh last? These translate to 210 Wh which means you could power your iMac theoretically between one hour and three hours. Is that enough?
  3. jerwin, May 21, 2018
    Last edited: May 22, 2018

    jerwin macrumors 68020

    Jun 13, 2015
    Power consumption depends on the GPU, CPU and memory; that's why apple specifies them. In my experience the GPU is much more likely to spin up the fans to audible levels than the CPU. I'm running m290x and i5. More heat output means more power consumed, so if you have an i7 or m395x, you may need more than 200 watts.

    so, use an accurate kill-a-watt meter (or the like), and run a realistic workload using the specific applications you need to run in the field. I mean, if you plan on using Logic Pro in the field, then someone else's Safari benchmarks aren't going to be of much use to you.
  4. joema2 macrumors 68000


    Sep 3, 2013
    That's probably not enough. My 2017 i7 iMac 27 is hooked to a UPS that measures power draw, whether the UPS is on line or not. It showed the following numbers:

    Idle with screen off: 40 watts
    Idle with screen on: 60 watts
    Play Youtube video in Safari: 80-100 watts
    Play local video in VLC: 100 watts
    Play video at normal speed in FCPX: 100 watts
    Fast forward through video in FCPX: 110 watts
    Render 1080p video in FCPX: 180-200 watts with 220 watts peak
    Play video at normal speed in Premiere Pro 2018: 180 watts
    Unigen Heaven benchmark: 180 watts

    The power bank you listed has 210 watt hours capacity. Whether that is theoretical battery capacity or measured after the AC inverter is unstated. Maybe 80% inverter efficiency is a good guess, so you probably have 168 watt hr usable capacity at the AC plug, and that assumes 100% battery efficiency.

    Depending on the load, that might run a iMac 27 less than 1 hr, maybe less than 45 minutes.

    Also if the peak AC output is only 200 watts, a surge above that would trip it off line and kill power to the iMac.

    You need a much higher capacity battery and inverter. The Ecoflow RIVER is one of the highest quality units, but it's only about 450 watt hrs:

    Probably something like the Goal Zero Yeti 1000 is what you'd want to run an iMac 27 for a few hours, it's $1300:

    If you have a 2016 or later MacBook Pro, you can run those via external USB-C DC power using something like this Anker PowerCore+ 26800. Since it's DC-to-DC with no conversion it's more efficient:

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