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I've been experiencing a very annoying problem lately. Often, I've got my MacBook Pro connected to power when I'm working from the office. At home, I often leave it unplugged until the battery is too low to continue at which point I plug it in.

The problem occurs when my device is connected to a power supply. My battery indicator shows 100% charge which is fine. But sometimes the battery starts draining and the menu bar icon says "Battery not charging," even when it's connected to a wall socket, and it keeps draining until absolutely dry. It doesn't even warn me the battery is running low because it shows "Power source: Power adapter" which I guess disables the Operating system low-battery warning. This has happened on multiple occasions.

I've already tried several things, I've swapped chargers, swapped wall sockets, started with as few tools/apps running as possible. But the problem comes back. I also can't really tie this to a specific app or behavior, AFAIK.

Does anyone know what might be causing this behavior and what to possibly do about it?

battery info screen shot

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  • What's the status of the charging LED on the MagSafe2 plug, yellow or green, when this anomaly occurs? – IconDaemon Apr 14 '20 at 15:17
  • I have noticed in the past when I have been using the my macbook pro (29W adaptor USB C type) that it will draw power from the battery as well as the power supply to meet the demand (heavy use of handbrake batch processing video files for example). Once done it then reverts to charging the battery. – Solar Mike Apr 14 '20 at 16:45
  • Could you use iStat Menus and see what the power draw is like? – Skeleton Bow Jul 11 '20 at 22:33
  • I think that this answer and other answers there have value, and may answer this. – uhoh Sep 2 '20 at 3:25
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There are two things that can be attributed to this:

  • There is a technical issue with your charger
  • The Battery Health Management feature (released in Catalina) can make it appear you have a charging issue.

Wrong charger

You are likely using the wrong power adapter; it's too "small" for your particular MacBook. Your machine requires the 87W power adapter.

If you take a look at Apple's support document Find the right power adapter and cable for your Mac notebook under the USB section, you'll notice that all of the adapters from the 29W that charges the MacBook to the 91W that charges the 16" MacBook Pro all look identical so it's quite easy to mix them up. While you can plug in any of these into any of the MacBook computers (plain, Air, or Pro) and while it will "charge," you won't get optimal results.

  • A "larger" charger can be used to power a "smaller" device. In other words, you can use the 91W charger from the 16" MBP to power/charge the 2015 MBA that only required the 29W charger.
  • A "smaller" charger should not be used to power a "larger" device. While USB-C will negotiate the power being delivered, if the adapter cannot supply the requested current, it simply won't be there.

What you're experiencing is what's in the second point. The adapter is connected (and detected) but it simply cannot supply enough power to charge and for you use the computer at the same time. If you notice, Coconut battery is reporting that it's charging with only 49W, yet the battery isn't charging. You're likely using the 61W adapter. (That number is a misnomer because that current is what it's drawing from the power adapter current, not what's going to the battery).

Battery Health Management in Catalina

As of Catalina (10.15.5) Apple has implemented a feature called Battery Health Management that will stop charging and allow it to discharge to a predetermined charge (about 80%) before recharging again. This happens even while the charger is plugged in and working.

You can learn more about Catalina’s Battery Health Management feature in the Apple Support Document About battery health management in Mac notebooks

Therefore, assuming you're using the correct wattage charging adapter, this could be perfectly normal behavior.

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  • Thanks for your elaborate reply. I just checked and both my chargers are 87w applestore-bought (online) chargers and both have the USB-C cable that came with it. The "charging with 49W" is what has me worried. I'm going to keep an eye on that stat and see what it says when i'm not experiencing the problem. This is I can't get head not tails on the situation because it happens everywhere, office, meetingroom, homeoffice, ... The only thing that's consistently the same in those situations is my Macbook. Maybe time for a repair/return? – ChrisR Apr 15 '20 at 22:55
  • Taking it to the Apple Store for diagnostics definitely couldn't hurt. I'm not a fan of Coconut battery because you can get that info for free with system_profiler, but it doesn't actually check the charger itself. This is a bit overkill, but this USB meter will tell you what's going on with your charger as it sends power to your MB – Allan Apr 15 '20 at 23:04
  • try a SMC reset. also, in the article above, battery health management, it states, "battery health management may reduce your battery's maximum charge when in this mode" NOT that It will discharge while plugged in OR indicate "battery not charging" .... This I confirmed with apple. Also, do you have that option enabled? I had a similar issue, in that it involved the battery but not these examples of malfunction. Battery Health Management is on by default btw. – Stumped Jul 15 '20 at 15:55
  • I am starting to experience this issue as well, and like the OP, I am using the correct charger (87W charger for a 2017 13" MBP). In fact, my OS just let my battery run down to 10% before it started to recharge. Right now, my battery has started to charge, and Coconut Battery reports that it's charging at 35-40W (I do appear to be accumulating net charge). – Weiwen Ng Jul 16 '20 at 15:47
  • Thank you for this post, especially for the part about Catalina 10.15.5 – skiabox Jul 30 '20 at 8:10
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What helps me (it's not a real solution but better than nothing) is: As soon as I see it misbehave I unplug the cord from the power supply and plug it back in. This resets something and it goes back to normal for a while.

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It's not 100% solved but I've experienced the problem a lot less since I started consistently charging my MacBook from the right side instead of left. There is some correlation between overheating and stopping charging but I haven't pinned the issue down just yet. But what I can tell is that when the MacBook stops charging (even when plugged in) it feels hot to the touch (and temperature sensors also indicate increasing heat being generated).

The battery drain did, however, occur again once or twice in the last 6 months but that was when my MacBook was under great stress due to running docker and zoom (with encryption enabled) at the same time.

So it just might be a hardware overheating issue that's kind of solved by switching site side you charge your MacBook. 🤷‍♂️

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I had this same problem and it stumped me for months. I swapped three different chargers and nothing worked!

It turned out that the problem was due to the USB-C cable going from the charger to the Macbook and I never noticed because when I was swapping out the chargers I was re-using that particular cord. The USB-C cord I had been using was apparently only able to carry about 85 Watts.

Long story short: When you swap out the charger, make sure you swap out ALL of the cables (including the USB-C one) with brand new ones.

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