[osigurdson]

USB-C is strange because the port that is used for charging is also used for communication and can act as a charger itself. I'm also not used to laptop chargers (MacBook and Thinkpad for example) being interchangeable. I'm always left wondering if I might fry something. I assume no, but it isn't worth experimenting with.

[sudosysgen]

You don't need to experiment. You're not going to fry your laptop. Unless the power supply is specifically designed to fry whatever it's connected to.

[osigurdson]

It would be great if we are at the point where as long as the plug fits, things will at worst cause no damage and at best work as expected.

As a contrived example, is it fine to plug a Thinkpad USB-C charger into a MacBook power supply? Or perhaps a random 5V USB-C charger with a 20V one (yes I am familiar with diodes)? It doesn't make sense obviously, but the plug fits and someone, somewhere with particularly bad cable management will do this. Does the USB-C standard ensure that sparks will never fly or is this responsibility of the end user?

[sudosysgen]

The USB-C standard does guarantee that there will never be any damage - any voltage over 5V normally has to be requested by the device. As long as the devices are standards compliant, nothing bad will happen.

The issue is devices that don't follow the standard, which can indeed be damaged, but what can you do about that.

[ksec]

If everything works according to standard, and if everything works in a perfect environment. Then Yes, it isn't an issue.

The reality is that charging at high voltage while being a high speed connection with direct controller on your CPU is problematic if not designed correctly. Aka MacBook Pro 2016.

[sudosysgen]

There is no standard environment issue. As long as your charger and device are compliant, it's fine. If they aren't, there is nothing that can be done no matter what you're using.

Charging nowadays requires a high voltage and manufacturers have decided they want to reduce the number of ports, so we have no choice but to have high voltages with a controller in the CPU. An alternative would be to have a charging controller that can be activated and take over, but that's again an issue no matter what standard you're using.

[osigurdson]

Good to know. Thanks!

[tinus_hn]

Or you use cables that manipulate the charging protocol incorrectly:

https://www.pcworld.com/article/424287/beware-bad-usb-c-cabl...

[PlanckMeasure80]

My official Raspberry Pi 4 USB-C power supply would like to have a word with you. It just sends out power.

[sudosysgen]

I can't edit my post anymore, but your power supply is just sending out 5.1v. It won't damage anything, you'll be fine. It would have been an issue if it sent out more than 5v, but that's not the case, so no correctly made device will be damaged.

[sudosysgen]

At more than 5v?