When charging my Macbook Pro (13 inch, mid 2017, MacOS Catalina 10.15.7) with the 61W USB-C Power Adapter from Apple, sometimes the "battery is not charging" warning start appearing from nowhere draining the battery (from every one of the 4 ports available).

By looking up the charging information (using Istat Menus) it appear that the Macbook think that the 60W charger is in fact a 12W one (and it appear that the intensity is negative i.e not charging):

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By unplugging/plugging back the USB-C cable (sometimes several times) all comes back to normal

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Why is this happening ? (Sometimes while the battery is full and still plugged, sometimes while charging)


  • The "battery is not charging" issue start happening early this year, but the Macbook had another issue with the logic board as well. After the logic board and battery being replaced, the issue is still here.

  • SMC reset didn't fix anything.

  • A full discharge, then a full charge didn't fix anything.

  • When using the power adapter from Apple and the USB-C cable on another device (unfortunately a phone and not another Macbook), it's charging normally.

  • When using another power adapter on the macbook, it's charging slowly (but coming from a 12W power adapter and a USB-A to USB-C cable that seems fair enough).

  • 1
    Have you tried another cable?
    – mmmmmm
    Commented Oct 19, 2020 at 8:54
  • Unfortunately no, I don't have another USB-C to USB-C Cable to use on my Mac. But using the original cable on a phone works normally.
    – Edd Growl
    Commented Oct 19, 2020 at 9:09
  • Yes but the phone won't need the full power so not a proper test
    – mmmmmm
    Commented Oct 19, 2020 at 9:15
  • Yeah, the phone can use as little as 5W and doesn't indicate what it's using. You may be able to time the charging rate of your phone to identify whether it's exceeding 12W, but I don't actually know how to do that.
    – Ezekiel
    Commented Oct 19, 2020 at 14:07
  • ok, but the cable don't seems to be damage and by unplugging/plugging it back it starting charging normal again. In other word, maybe the cable is not the issue here ?
    – Edd Growl
    Commented Oct 19, 2020 at 14:29

2 Answers 2


When charging my MacBook Pro (mid 2017, macOS Catalina 10.15.7) with the 61W USB-C Power Adapter from Apple, sometimes the "battery is not charging" warning start appearing from nowhere draining the battery.

There are a couple of possibilities that can be attributed to this:

Battery Health Management

This could be expected behavior. With the release of Catalina (10.15.5), there is a feature called Battery Health Management that will actually stop the charging of the battery at a certain battery charge range. This "battery not charging" message is perfectly normal when this function/feature is enabled.

Faulty USB Mux Chip

There have been reports that the USB Mux chip (TI CB3215) is faulty. This chip is what negotiates the charging power to be delivered from the USB-C (USB-PD compliant) power adapter. It starts off with a 5V nominal voltage, but then can go as high as 20V at about 3A (≅ 61W). The full spec calls for up to 20V @ 5A or 100W, but (obviously) can be lower due to a lower overall wattage rating.

This is expected given that the correct charger for the 2017 MacBook Pro is the 87W charger. See the Apple Support document Find the right power adapter and cable for your Mac notebook. If you use a power adapter with less than the required wattage, your MacBook will not be able to supply enough power for all of it's functions - charging and powering the computer. In this case, it was using all available power to run the laptop and there wasn't any left to charge the battery.

Your charger is likely good

When using the power adapter from Apple and the USB-C cable on another device (unfortunately a phone and not another MacBook), it's charging normally.

"Normally" is relative here. If it's from a MacBook and USB-C PD compliant (which Apple chargers are) it would be sufficient enough to charge the phone at what appears to be a "normal rate." Being that it's USB-C, it would conform to the USB Power Delivery Specification (USB-PD) where the current is negotiated to the highest possible. As mentioned earlier, it would start off at 5V then negotiate from there. As most phones use a 5V and a 2-2.5A charger anyway, even without negotiating power, the adapter is delivering the maximum (what the phone will draw) to charge the phone. This means your charger is likely working as it should. However, a proper test would be to try that charger on a different MacBook. If you see that it negotiates anywhere near it's full 61W, then you've confirmed it's viability.

When using another power adapter on the MacBook, it's charging slowly (but coming from a 12W power adapter and a USB-A to USB-C cable that seems fair enough).

This is also expected. Most USB-A chargers only supply up to 12 watts of power. There is no power negotiation with these chargers. When connected to your MacBook, it will receive the 5V from the adapter, the Mac will attempt to ask for more but since it will not get a response, it will just continue to draw the 12W available.


Some of this, as described is normal behavior if Battery Health Management is enabled. If you suspect your adapter, you can use aftermarket USB-C chargers with confidence but I always recommend getting quality adapters and cables from well known vendors like Anker, Belkin, StarTech, etc. However, there is the possibility that the USB mux chip that regulates the charging is failing or has failed. Apple will require a replacement of the logic board, but there are board repair facilities that can replace that single component.

  • I'm using the apple charger provided by Apple when I bought my Macbook, why are you saying that this is not the proper one ? Also, my question is more about how the Mac claims sometimes that the charger is 12W and sometimes 60W as it should always be 60
    – Edd Growl
    Commented Oct 20, 2020 at 8:53
  • Just went on apple website and the correct charger is the one I use (61W) as the MacBook Pro is the 13inch (sorry for the confusion as I didn't mentioned it on the question)
    – Edd Growl
    Commented Oct 20, 2020 at 9:01
  • For some reason, I read that you had a 15" not a 13". I'll update my answer. BTW, what does "Adaptaeur Secteur" mean. When I translate it I get "Sector Adapter" which makes no sense - I guess it doesn't translate "correctly."
    – Allan
    Commented Oct 20, 2020 at 14:01
  • It's the Power Adapter (in french, we refer as "secteur" the 220V houses sockets)
    – Edd Growl
    Commented Oct 20, 2020 at 14:18
  • 1
    It will stop charging and allow it to dissipate to about 90-ish percent and hold it there if coming from a full charge and you plug in. However, if coming from lower, it should charge it past 85% then hold it around the 90-ish mark. If your Mac isn't doing either of those (or you disabled it) and you still have the problem, it's time to have it checked out. Also, try a different port for charging, but remember there is 1 mux per 2 ports. So if you only have two ports (13" has 2 and 15" has 4), then both ports will exhibit that problem.
    – Allan
    Commented Oct 20, 2020 at 15:02

After a while I had the chance to try a spare 96W power adapter from Apple.

It looks like the only non fonctional component was the power adapter itself (when trying my usb cable with the 96W power adapter, everything goes as expected).

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