I just went to charge my kitchen scale and it wouldn’t work until I dug out a USB-A -> C cable and plugged it into my desktop…
It just reminded me of how many devices like that I have. This scale, my wife’s sound torc, some car jumperstarters, and I think a one or two more…
I assume it’s because they just slap a usbc port on a dumb 5v circuit that doesn’t have a power negotiation controller. So the cable and the charger cant figure out the power needs of the device are and just never send any.
PD includes a 5v option, so you’d think that chargers would default to a dumb 5v/4.5w with no other input, but apparently not… It’s probably something to do with the overcharge protection, or to not (further) harm a device with a damaged charge controller.
Or it could be that my PD chargers are pre pandemic and PD 3.1 fixed this.
Well, I’d expect that if they allowed 5v through but with a low current limit (I think the default 5v standard states quite a low current allowance). They could catch anything drawing too much and shut the port off until it detects disconnection/other reset.
I mean, if they’re thinking about protecting a downstream device, adding this logic would make more sense than just not supplying any power unless a negotiation is made.
In any case, since standard USB ports on a computer will output 5v without anything being negotiated, then it’s really no less safe than any other USB port in that regard.