M1 2021 MacBook Pro indicates charging, but drains battery instead

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Level 1

13 points

M1 2021 MacBook Pro indicates charging, but drains battery instead

The MacBook is connected to a charger with a USB-C cable (not Mac-Safe) - both genuine Apple - and the charging indicator says that the charger is connected and the battery is charging. However, after some time the battery is drained, even if the Macbook isn't in use.

I literally need to power down the MacBook and remove the charging block for some time from the power outlet. When re-connecting everything goes back to normal.

The attached image shows that despite the timeline saying the charger is connected, the battery is literally drained at a constant rate, as if instead of charging the battery, the battery is 'charging' the electricity grid.

This is an issue I experienced in the past, it then vanished and now it is back. It is very unlikely to be an issue with the charging block, nor an issue in the electricity supply. This, because I have multiple charging blocks at different locations and at all location this issue occurs randomly. Nor does it seem to be a battery issue, as the battery health says 90% Normal and I have otherwise perfect battery performance.

[Edited by Moderator]

MacBook Pro 16″, macOS 15.6

Posted on Aug 25, 2025 05:13 AM

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Answer 1

Aug 25, 2025 02:15 PM in response to mwille64

If using a USB-C cable to charge while running at the same time, remember that there are THREE different classes of Power Delivery through different USB-C cables.

The standard USB-C cable can carry up to 60 Watts from a power adapter. That is NOT enough to charge AND Run a 16-in MacBook Pro. That could explain the declining charge battery while attempting to charge..

some Premium USB-C cables can carry 100 Watts power, and this is about the right amount for normal charging while running of that MacBook Pro.

some Super-Premium USB-C cables can carry 240 Watts power, and that might be able to Fast charge your Mac, possibly even while running.

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Answer 2

MartinR

Level 7

23,541 points

Aug 25, 2025 09:48 AM in response to mwille64

mwille64 wrote:

I have multiple charging blocks at different locations and at all location this issue occurs randomly.

Then it would appear to be an issue with your MBP and/or the chargers or cables you are using.

If you have AppleCare Plus, contact Official Apple Support to start a service ticket.

If not, contact Apple to start a diagnostic/repair service or set up a Genius Bar appointment.

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Answer 3

Aug 25, 2025 10:17 AM in response to mwille64

mwille64 wrote:

The MacBook is connected to a charger with a USB-C cable (not Mac-Safe) - both genuine Apple - and the charging indicator says that the charger is connected and the battery is charging. However, after some time the battery is drained, even if the Macbook isn't in use.

I literally need to power down the MacBook and remove the charging block for some time from the power outlet. When re-connecting everything goes back to normal.

The attached image shows that despite the timeline saying the charger is connected, the battery is literally drained at a constant rate, as if instead of charging the battery, the battery is 'charging' the electricity grid.

This is an issue I experienced in the past, it then vanished and now it is back. It is very unlikely to be an issue with the charging block, nor an issue in the electricity supply. This, because I have multiple charging blocks at different locations and at all location this issue occurs randomly. Nor does it seem to be a battery issue, as the battery health says 90% Normal and I have otherwise perfect battery performance.

MacBook Pro 16″, macOS 15.6

On the M-series A SafeBoot Start up your Mac in safe mode - Apple Support will sort many anomalies

Login and test. Reboot as normal and test. Caches get rebuilt automatically.

The current stable release of Sequoia including bug fixes, security updates is macOS 15.6.1

Keep your Mac up to date - Apple Support

ref:

If your Mac battery will not charge—

If your Mac battery won’t charge - Apple Support

If your MagSafe cable or power adapter isn't working

Unplug the power adaptor from the wall, wait 60 seconds and then plug the adaptor back in.

If your MagSafe cable or power adapter isn't working - Apple Support

If your Mac battery status is “Not Charging” - Apple Support

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Answer 4

mwille64 Author

Level 1

13 points

Aug 28, 2025 01:19 AM in response to leroydouglas

Sorry, this answer was meant to be for @Grant Bennet-Alder

This is in so far incorrect, as the 60 Watts are drawn under maximum GPU load. My M1 has never and will never hit this consumption as it is used for regular office usage (browsing). The worst case scenario is some multi-tasking, which on average takes about 40 Watts.

The power supply is an Apple 87 Watts with a matching USB-C cable (also genuine Apple). This is more than enough power to work and charge at the same time. It certainly is enough to prevent a drastic discharge rate as shown in the screen shot.

The observed discharge rate can only be explained if no power supply is connected. However, the screen shot clearly shows that the MacBook believes that a power supply is connected.

So either the OS is reporting wrongly or there is some other mechanism at work that is not explained by your answer.

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Answer 5

mwille64 Author

Level 1

13 points

Aug 28, 2025 01:32 AM in response to Grant Bennet-Alder

My MacBook is always up to date in terms of stable releases (assuming that the regular updates are stable).

I always try to first unplug the power adaptor for 60 seconds as I'm aware of the fact that the power adaptor switches of when it detects anomalies in the electric supply. I'm reporting this, because I had the situation in the past and it came back. The two power supplies I use both show the same effect, in the office and at home. I can't imagine that both locations suddenly show electric supply issues, nor do I believe that both Apple power supplies suddenly decide to have an issue. In the particular incident report, the MacBook did not charge after disconnecting and reconnecting the power supply.

Aside the screen shot shows that the power supply did not switch off, power supply is detected by the MacBook. In matter of fact exactly at the red bars you will notice to short disconnects of the power supply. However, the MacBook continue to discharge until I switch off the MacBook and switch it on again.

To summarise, this is not a power supply issue, I believe the MacOS is reporting wrongly. Again, this is a returning issue. It looks like something was fixed and then it broke again.

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