Oh? Everyone else seems to think the mechanisms are sufficient for safety.
> This wasn't my point, despite me addressing negotiation in another comment.
I still don't understand your point, unless it's a failed effort at pedantry.
Also the original comment was unclear; they've edited to clarify. But of course, I'm the bad guy on HN for not being able to read minds.
E: I realize my GP comment was also unclear. I should have said "excessive" voltage, not improper I suppose. "Improper" in my head meant outside the rated voltage for either end/the cable. I'm not the one being a pedant here.
Which is exactly what GP was saying in the very part that you quoted:
> chargers and cables are advertised with the wattage they support, but it's really the voltage and current that matters.
and what you agreed with in that very same comment:
> Also, it arguably does have everything to do with volts
USB-PD on USB-C negotiates the highest voltage your device and charger will support.
You can buy a 30W USB-PD charger that supports a smaller subset of voltages than a 20W USB-PD one, and in practice will deliver less power to your device because the voltages both like don't line up well.
What actually is supported by each tends not to be specified/disclosed-- or if it is, it takes a lot of digging to figure it out.