Battery (last 12 hours) in activity monitor issue

Discussion in 'macOS Sierra (10.12)' started by Cycling Asia, Dec 1, 2016.

  1. Cycling Asia macrumors regular

    Mar 19, 2016
    Good day all,

    On my 2011 MBA I finally made the plunge do upgrade to Sierra from El Captian. I performed a clean install off a usb and have had no issues except this one (so far).

    I opened the Activity Monitor app to check my rate of battery drain and the battery usage graph (last 12 hours) was flat at 80% (the battery was at 80% when I checked). I didn't think much of it until I the activity monitor app again, now the batter was flat at 50% (battery was at 50%). So the battery usage graph has become a current battery level graph.

    Has anyone else had the same issue occur?

    This is the graph. The battery was at 100% when I started (about 2 hours ago). As you can see, the graph is not showing the battery over the last 12 hours, just the battery now (kind of makes the graph useless)
    Screen Shot 2016-12-01 at 10.55.41 pm.png
  2. elf69 macrumors 68020


    Jun 2, 2016
    Cornwall UK
    Another user had similar issues.

    They had to let battery die and recharge 2-3 times then the meter started to work properly.

    Might be worth trying a few cycles letting battery fully die, it worked for them after the upgrade.
  3. Cycling Asia, Dec 1, 2016
    Last edited: Dec 6, 2016

    Cycling Asia thread starter macrumors regular

    Mar 19, 2016
    Cheers I'll give that a go over the weekend.

    Edit 1:

    So, I've run down my Mac a few times, (I also performed an SMC and PRAM reset) and the graph does appear to change now, but not while the app is open. Oh well.

    Slightly off topic, but in order to run down my battery I had set up a simple site on my local server (apache) to play an mp4 in a video tag. I loaded this in Safari and let it play (I had also installed coconut battery in order to monitor the battery state as this provides current power consumption). When running Safari, coconut battery was showing a power consumption of just over 8 watts. For fun I decided to switch to Firefox, and playing the same video from the same page, the power consumption was 13 watts. Just something to think of when considering different applications.

    Edit 2:

    So, this evening I checked the Energy tab in the Activity Monitor and it appeared to be correct, showing a mix of charging and discharging. All good then? Not quite, I restarted the machine and all battery history is gone. Oh well - I guess I cannot restart my machine if I want to maintain it.

    Perhaps I should log a bug.

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