AIUI, the USB-PD spec requires fall-back to 5V with a maximum of a 3A limit in the absence of negotiation for something different. This is to prevent a meltdown of 3A rated cables (which won't allow a 5A mode to be negotiated). I would be surprised if the Pi5 PSU does something non-compliant in this respect, but I can't easily test because I don't have a 1R 27.5W resistor.The official PSU doesn't have a 5V, 3A mode:. I interpret "5.1V 5.0A" as specifying the maximum current, not the actual default output.
I agree that it will make little difference in practice, as long as the cable is adequate -- but even with a 5A rated cable, PD negotiation is necessary in order to get more than 3A.
. I interpret "5.1V 5.0A" as specifying the maximum current, not the actual default output.In the general case I'm certain you're correct. But this thread is specifically about the official 27W PSU and that has a captive cable which I presume is suitably rated. Or it wouldn't be on sale.
Statistics: Posted by thagrol — Fri Sep 13, 2024 9:34 pm