MacBook Pro 16 charging stops and starts while connected to power when I open any application

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Level 1

8 points

MacBook Pro 16 charging stops and starts while connected to power when I open any application

I have a 10 day old custom built 2019 16 inch MBP with a Core i7 and 32GB of RAM. The machine does not have T2 encryption enabled.

While the MBP is connected to the power adapter, it cycles between charging and battery every time I open a new application or a power hungry browser tab. So it seems to be correlated with CPU power spikes.

When it does this, the charging indicator changes to battery and back to charging again within 5-10 seconds. It also dims the display and makes the charging chime noise which is very annoying.

It does not matter which of the 4 thunderbolt ports the power adapter is connected to. This still happens.

It happens even when the battery reaches 100% charge.

Has anyone else had this experience?

Posted on Sep 9, 2020 8:26 PM

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Answer 1

Top-ranking reply

neuroanatomist

Level 9

50,359 points

Sep 9, 2020 8:31 PM in response to racer-x

It's normal for your Mac to draw power from the battery when on AC, if it needs more power than the charger can provide (I've seem my 16" MBP draw 125 W, for example). It's not normal for it to make the 'charger connected' sound or dim the display, however. I'd try an SMC reset, and if that doesn't correct the issue, contact Apple Support.