Why does MacBook Pro 16" give an electric current feeling when charging?

[sekoitus]

You know, when your hands move over the chassis. This only happens if I use the default charger, with the short cord. If I add the long cord (that doesn't even come boxed in with the new MBPs anymore), then the electric current feeling doesn't happen at all.

What is so different with the default charger cord and with the long cord added in? Why one causes the electric current feeling and the other does not?

Please don't ridicule me if it's a super simple reason

 

[lixuelai]

The default plug is not grounded, the extension cable is. Always been like this on Macbooks.

 

[JPack]

The default plug is not grounded, the extension cable is. Always been like this on Macbooks.

Correct.

For safety reasons, always use a power extension cable as it has grounding.

 

[theluggage]

For safety reasons, always use a power extension cable as it has grounding.

That’s always good advice.

However, just to be clear, that ”feels like the case is vibrating when you stroke it” sensation is a well known effect that has been present on aluminium-cased Macs since forever (my 2011 MBP does it), only involves tiny amounts of current and isn’t dangerous or a sign of an electrical fault.

Anything more than that, or if in doubt, get your power supply checked out ASAP.

 

[pshufd]

I prefer the grounded cords because the prongs in plugs that are used a lot can get loose so that the brick just falls out. I've noticed that this happens a lot in airports. The long cable can be a pain to carry when you're traveling but it gives you a lot of flexibility in charging in hotel rooms and in airports. I was a bit surprised that the grounded cable wasn't included in the 2021 MacBook Pros but I have a couple of these in my parts box from old Magsafe I and II adapters that failed. I kept the grounded cables and the short plugs.

The grounded cable is $19 and it gives you flexibility and gets rid of the fuzzy feeling on your MacBook. But long-time MacBook Pro users may have spare cables from older systems. If you know someone with a long history of using MacBook Pros, you could ask them if they have a spare cable.

 

[Nocturnal-G]

Has anyone bought a new grounded cord lately? Are they still 2.5A?

The connector that comes with the 2021 MBP is 7A.

 

[TinyMito]

The default plug is not grounded, the extension cable is. Always been like this on Macbooks.

I wonder if that is because it's a compromise on the design again - the prong to be foldable.

 

[Hieveryone]

It has happened to me, but I don't sit idle. I usually turn it off, unplug it, etc until I don't feel it again. Sometimes it has been more frustrating than other times. I have not had it happen recently and in a while *knock on wood*