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by raverbashing 1138 days ago
> My usb-c ecig won't charge from that

Sounds like a "Fake" usb-c. Actually not fake because the usb-c is the connector, not the standard behind it

So I'm not surprised it doesn't charge, it's a "pretend USB-C" thing from China
1 comments
vladvasiliu 1138 days ago
Sure, as a technically inclined user, I can understand that.

It actually is a Chinese brand, but not some one-off brand bought off Ali Express. It's a device bought from a reputable store in France with a name that I've seen around for several years (Vaporesso). Sure, that fact, in and of itself, is not enough to guarantee that corners haven't been cut and that the product is actually up to spec.

But, as a random consumer, how am I to know that it's "a pretend USB-C"? It looks exactly the same as my headphones, comes with the exact same-looking cable. There are no markings on it. The usb-c ports on my laptop have a bolt icon next to them, but its usb-c charger doesn't have any marking. They also don't say it shouldn't be used with anything other than the laptop it came with, and actually is able to charge my headphones and my mom's usb-c phone.

Even though I've kinda followed the talks about PD, negotiation, etc. its still not clear to me why this particular combination doesn't work. I was under the impression that, lacking any negotiation, ports should default to the basic 5V 500mA. So my fat laptop charger should be able to at least trickle-charge the e-cig.

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crote 1138 days ago
Because USB-C does not have a defined "upstream" and "downstream" side of the cable, a user could connect two chargers together. This is obviously a bad idea.

To prevent this, a USB-C charger is only allowed to provide power on the cable once it senses a downstream device on the other side. A legacy USB-A to USB-C cable always applies power, though, as this does not provide any danger.

Some low-quality brands think they are smart and leave out the two $0.001 resistors needed for the device to advertise itself. This means it will only work with a USB-A to USB-C cable, and not a real USB-C charger.

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