Macbook Pro Battery Drain

Discussion in 'Mac Basics and Help' started by gadgetgirl85, Sep 25, 2017.

  1. gadgetgirl85 macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
    #1
    I have a 2015 MBP and over the past couple of months my battery has started to drain really quick. In 2.5 hours I have used 40% and that is without watching any videos, doing anything too intensive other than some Word Documents. I've taken it into Apple and they say my battery is fine. According to my battery app its probably at 80% health. When I check, there is also nothing significantly draining my battery. Any ideas? Thanks :)
     
  2. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
  3. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #3
    I'll take a shot.

    If this MBPro is used every day, you might want to use a different Mac for a few days. If you don't have an extra one, well, see how well the MBPro works under the following conditions.

    The first thing I'd try is booting into Safe Mode and see how that affects the battery drain rate.
    https://support.apple.com/en-us/HT201262

    Be sure to read the heading "Some features aren't available in safe mode", and see if any of those are things you can't do without.
    Even if you can't do without it, try booting into Safe Mode anyway and see if the feature is available. For example, Wifi might work fine, despite the warning.

    Some people can't stand Safe Mode, so make sure you can work with it for a few hours. After booting into safe mode, use it the same way you did that led to the 40% battery drain in 2.5 hrs.

    I'd turn the screen backlight down to zero, then bump it up to not more than 4 for the duration of the test. How does that brightness level compare to the screen backlight brightness you usually use? The backlight takes a significant amount of current when it's on.

    If you can manage it, try turning off all networking, both in Safe Mode and in Regular Mode. I'm wondering if something might be throwing a lot of network traffic around. It's a pretty easy thing to change, and if you then work solely in Word, you can generally get an idea of the difference between having a network and lacking one. If you use Bluetooth, I'd turn that off, too. Radios (wifi or BT) can use significant power when transmitting, so if you happen to be farther away from your wifi base station, or are burning up the airwaves with Bluetooth, that may affect battery life.

    Finally, I'm a bit unsure what you mean by "used 40%". Do you mean it went from 80% to 40%, the 80% being the "80% health". Or maybe you mean it went from 100% of 80%-health down to 60% after 2.5 hours. If your battery is at 80% health, that basically means it can hold 80% of the original full charge. To determine the equivalent time at 100% battery health:
    2.5 hrs / 0.8 = 3.125 hrs​

    So basically, if battery health were at 100%, it would have taken about 3.125 hours to drain from 100% to 60%. As a ball-park figure, that doesn't seem completely crazy to me.

    A better way to calculate battery consumption is using mA-hrs (millamp hours). The original nominal battery capacity in mA-hr should be in System Profiler / System Info, along with the current max charge level it can hold. It would be useful to know what the max capacity and the number of cycles is for your Mac.


    Those are some things that come immediately to mind, but I might be able to think of more.

    Your battery parameters (cycles, capacity, etc.) from System Info would be good to post.
    Oh, and your OS version number.
     
  4. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
    #4
    Thank you Chown! using 10.12.6

    and

    Charge Information:

    Charge Remaining (mAh): 2646

    Fully Charged: No

    Charging: No

    Full Charge Capacity (mAh): 7987

    Health Information:

    Cycle Count: 408

    Condition: Normal

    Battery Installed: Yes

    Amperage (mA): -968

    Voltage (mV): 11169
     
  5. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #5
    Thanks for posting that. It appears to be at about 30% of nominal full battery capacity.

    Can you give it a full charge, then open System Info and post the fully-charged info, so I have that to compare with?

    Also, if you have a percentage battery indicator in your menubar, what percentage appears there when the battery is at full charge (or as close to full as you can get it).

    I'll do some poking around for system specs on that model on Wed, and see what I can find. I don't recall the projected battery lifetime for that model, but I think it's likely around at least 1000 cycles. If it's rated for 1000 cycles, you have about 60% of that left. If it's rated for 1200 cycles, that's 66% left; if for 1500 cycles, about 72% left.

    The current drain (Amperage (mA)) of -968 mA doesn't strike me as out of line, depending on what it was doing at the time.
     
  6. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
    #6
    Thank you :) I will report back tomorrow with those details.
     
  7. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #7
    Please post the "Model name" identifier, too. It will look something like MacBookPro15,2, but you might have different numbers.

    It should be near the top in System Info, or paste this command line into a Terminal window:
    Code:
    sysctl hw.model
     
  8. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
    #8
    MacBookPro11,5
    Charge Information:

    Charge Remaining (mAh): 7668

    Fully Charged: Yes

    Charging: No

    Full Charge Capacity (mAh): 7792

    Health Information:

    Cycle Count: 409

    Condition: Normal

    Battery Installed: Yes

    Amperage (mA): -2248

    Voltage (mV): 12598
     
  9. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #9
    Here's the specs for that model, assuming the 2.5 GHz CPU speed:
    https://everymac.com/systems/apple/...l-graphics-mid-2015-retina-display-specs.html

    It's stated as a 9 hour life with a 99.5 watt-hr battery.

    That watt-hr number is pretty close to what your posted data shows:
    1 watt = 1 volt * 1 amp
    12598 mV = 12.598 V
    7792 mAh = 7.792 Amp-hours
    so: 12.598 * 7.792 = 98.16 Watt-hours​

    That "fully charged" state is roughly 98% of the original spec for that battery. I think that's reasonable after 409 cycles.


    The datum that really catches my eye is this:
    Amperage (mA): -2248​

    This strikes me as excessive.

    To get a 9 hour life from a roughly 100 watt-hr battery, it should pull about 11 watts per hour (100 / 9 = 11). At 12.5 volts, that's about 1.1 amps, or 1100 mA. The number shown is roughly twice that. So whatever the MBP is doing, it's doing it at a rate that will give about half of the stated 9 hour life, or about 4.5 hours max.

    Which leads to the question: What are all the apps running at the time this data was collected?


    It might be worthwhile for you to use the Energy pane of Activity Monitor.app and see what it says.
    https://support.apple.com/en-us/HT201464

    There are several columns in that display, and you can click on a column title to sort by the value in that column.

    I'd start by sorting on the general Energy Impact column, and see which apps are the biggest consumers. Next, I'd look in the column for High Performance GPU, and see which apps need that. Your Mac model has 2 graphics adapters (GPUs), and if any app needs the faster one, your battery life will pay the price for it.

    If you post screenshots of your Activity Monitor Energy pane, I can see what's happening.
     
  10. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
    #10
    Thanks! Yeah I don't know whats going on..I'm only running Safari... I'll post that info for you
    --- Post Merged, Sep 27, 2017 ---
    Here it is (attached)
     

    Attached Files:

  11. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #11
    Yeah, that definitely looks like Safari is burning up the battery. It's not due to the GPU.

    There's a little right-pointing triangle at the left of the Safari name (it's called a "disclosure triangle"). Click it. I'm guessing it will expand to show Safari's sub-processes, which should basically be one "helper" process for each tab or window Safari has open. Please post a screen shot of that, as it may shed more light.

    I'm guessing about the disclosure triangle because I don't have 10.12 on anything handy, so I can't check it here.


    Since the excess power doesn't appear to be tied to GPU usage, my next guess is that Safari is consuming CPU for some reason.

    Safari's CPU use depends on how many tabs or windows it has open, and what's in each of those. The CPU pane of Activity Monitor will show CPU consumption. If Safari has a disclosure triangle, click it to expand and view the "helper" processes before taking a screenshot.


    I take it all your recent posts with info, screenshots, etc. have been made in Normal Mode, rather than Safe Mode. If they're in Safe Mode, i.e. Safe Boot is active, then please state that clearly.
     
  12. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
    #12
    I am doing all this in regular mode. Here's the screenie. Thanks so much for your help!
     

    Attached Files:

  13. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #13
    Well, that shows which tab or window is burning the most energy. It's this very site. So my first guess on that is an ad, but that's just a guess.

    The CPU usage might add some detail as to what's burning the power.
     
  14. gadgetgirl85 thread starter macrumors 68040

    gadgetgirl85

    Joined:
    Mar 24, 2006
  15. chown33 macrumors 604

    Joined:
    Aug 9, 2009
    #15
    It does. It tells me that whatever page from this website is loaded when you took that screenshot, it's burning up about 10% CPU. That strikes me as high.

    I can't think of a good reason why that might happen, so my first guess is ads.
    My second guess is that somehow some JavaScript is running frequently or possibly looping.

    If you close the MacRumors website in Safari, and then look at the CPU pane, what does it show? It might take a minute for things to settle down.

    If you quit Safari completely and look at the CPU pane, what does it show? What does the Energy pane look like with Safari quit? If you let it stabilize for a few minutes, does the Energy Impact graph go down? Does the Time Remaining estimate go up after a few minutes? That estimate seems to use an averaging algorithm, so you'll have to let it sit there for a few minutes before it recalculates the Time Remaining estimate.

    With Safari quit, does the WindowServer %CPU go down? If so, then it's Safari that's causing WindowServer to burn CPU. If not, then something else is doing enough drawing to raise WindowServer's CPU usage.

    With Safari quit, does Safari Networking also terminate? Here's another MR thread on that process being a hog:
    https://forums.macrumors.com/threads/safari-massive-cpu-hog.1598831/

    You could try a solution in that thread of creating a new user account and seeing if you get similar CPU usage from Safari in that account. You should logout of your current account and login to the new one, rather than using fast user switching.

    You can find more info by googling: macos safari networking plugin

    Another thing to try is to run Safari, then turn off all Internet Plugins in its Preferences window. Do it temporarily, then visit the MR website and see if the CPU usage heads up to 10% again. If not, then you might have an old or malfunctioning plugin. You'd then have to list all your plugins, and check their version numbers against what the latest versions are, or the versions with best 10.12 OS compatibility. You could try enabling them one at a time and see which one, if any, leads to increased CPU.
     
  16. steve23094 macrumors 68000

    steve23094

    Joined:
    Apr 23, 2013
    #16
    I have fallen victim to rogue ads on this site before. They activated my discreet GPU and therefore chewed through my battery. One of the many good and valid reasons to use an ad-blocker.
     

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