Let me introduce you to the magic of USB Power Delivery, an incredible standard that brought forth USB-C devices that can’t work at all with USB-C chargers, since they don’t speak the required protocol.
Slow charging is compatibility mode. That’s a tad better than not working at all.
Yay to the USB standards bodies, and the many non-standards implementers, I guess.
Correct! And not just the charger and the device, also the cable needs to have the right e-marker chip (> 5 A), speak the protocol and confirm that it can carry the requested current during negotiation.
Let me introduce you to the magic of USB Power Delivery, an incredible standard that brought forth USB-C devices that can’t work at all with USB-C chargers, since they don’t speak the required protocol.
Slow charging is compatibility mode. That’s a tad better than not working at all.
Yay to the USB standards bodies, and the many non-standards implementers, I guess.
it’s not even just unsupported protocols, it’s also about voltage levels the charger and device supports
Correct! And not just the charger and the device, also the cable needs to have the right e-marker chip (> 5 A), speak the protocol and confirm that it can carry the requested current during negotiation.
Just look at this teardown. High-current USB-PD cables are electronic devices of their own right: https://www.chargerlab.com/teardown-of-apple-240w-usb-c-charge-cable-a2794/