Would Macbook Pro shutoff the power adapter to let the battery work?

By the way, I found this link, If your USB-C power adapter isn't charging your Mac laptop – Apple Support (UK)

Unplug the power adapter from the wall, wait 30 seconds, then plug the adapter back in:

• If your Mac laptop starts charging after you've plugged the power adapter back in, this may indicate an issue with line noise (disruption caused by stray electromagnetic signals) from your plug socket. The power adapter will shut off automatically when its built-in voltage protection feature senses line noise from a socket.

So, it must be a problem with the power socket. The adapter simply protects itself, and the MBP. I changed the extension cord and the socket bar. I like the way Apple protects its products. Also, special thanks to Grant Bennet-Alder for giving me the hint look further.

ku4hx wrote:

" ... the adapter is too tall"

Too tall for what? If it doesn't fit in the space where your wall sockets are, you'll need to plug in somewhere else. Or get a short high capacity extension cord.

Two pins has no bearing on the issue, that's just the design that adheres to your country's electrical codes.

The two pins are thinner than the standard holes of the sockets. Usually the sockets have 2 holes and one fixed pin (grounding), but the Apple's connector has only 2 pins.

Anyway, I was thinking that the MBP can't stop the adapter working, so it must be that the pins had moved within the hole and disconnected the power. But, I asked as I am new to the Mac-world.

Why too tall? The adapter is connected to a multi-socket bar on the floor, so the adapter stands upright. The socket bar doesn't move, so it can only mean the sort-of loose pins move about, if knocked by someone/something. The socket holes have special springs to hold the pins in place, but they may not touch the inside connectors, as they are thinner. Maybe there are 3-prong AC plug connectors around, as shown by Grant Bennet-Alder, but with thicker pins, matching European size. 3 pins will not move, even if two of them are thinner.

Thank you both for responding.

Observing the matter further.

I shutdown the MBP yesterday night and powered it on at 9 a.m. MBP was connected to power through the adapter, before powering up the MBP. Exactly at 9:39 the MBP shutoff the electrical connection. I noticed this because the screen suddenly darkened slightly. It is on low power mode on battery. I'm going to work on battery until it asks for the electrical power, more or less around 34%. It'd make a sound.

Yesterday, the cord was connected, the electricity was supposed to flow the adapter, but the adapter was cold. Today, I took off the cord and the adapter off electricity. Will work on battery. Tomorrow, if the same situation happens, I'll keep the cord and the adapter on. Just to check.

It'd be interesting, if the MBP can do this, to act in a way to save the battery life, i.e, put the adapter off. But it would be nice, if it use up to 80% and go back to electric power. The MBP practically never leaves the desk. But, why should it do such a thing?

According to System Information, the battery is good, cycle counts at 203. This 15" MBP was bought in May 2019. I'm the second owner.