USB Charging Current ?

[jaizan]

I'm preparing for a holiday. I like to travel light.

I've got 2 small "Anker Nano" phone chargers, with US 2 pin plugs 100~240V input and high power USB-C output. These get good reviews & are ideal for travelling in Asia.

Unfortunately, my toothbrush and one other device have USB-A connectors on the bespoke charging cables.
So I tested one device with a USB-C male to USB-A female connector, so I could use the device & normal cable on the USB-C charger.

This did not work. Eventually I established that the cable wasn't working.

What I don't know is if the cable had already failed, or if I've managed to configure a non-approved USB combination & overload the charging cable.

I believe USB-C cables are supposed to contain a chip to tell the charger how much current they can handle.
However, in the absence of that I would have expected a very low default current. Perhaps not low enough ?

[GrahamPlatt]

Using the wrong USB cables can damage your equipment…

https://en.m.wikipedia.org/wiki/Benson_Leung

Something I was unaware of. I thought “a cable’s a cable” (well, I was aware some USB cables only charge, while some do charging + data transfer). Just been lucky so far.

Edit: The meat of that is here: https://www.engadget.com/2015-11-04-goo ... ables.html

[Urbandreamer]

It's a mine field.

As original spec USB-A was 5V at 0.5A (2.5W).
That got pushed to 1A as standard (5W).
Then people started to draw 2A (10W).
I have a dumb adapter that can supply 3A (15W).

By now we are very much into the territory of melting wires and connectors.
Heat is I^2 * t.

In order to supply Iphone and computer rates of charge they up the voltage, needing to negotiate the voltage.
Hence the chip in good USB leads, though dumb cables can signal reduced capacity with a couple of resistors.

NOTE it's NOT the connector. USB-C may in many ways be a better plug and socket, but that is all USB-C is. It doesn't dictate what is provided by equipment with such a socket.

Ps, a quick check of Amazon and Oral-B USB chargers claim to be 0.9W, though also that USB is 110-240V!
https://www.amazon.co.uk/Electric-Tooth ... hdGY&psc=1

[Infrasonic]

Buy branded USB/ HDMI/ Displayport cables, adapters et al and you should be ok with things being to official specification around power and data delivery.

Just watch out for kit that is USB C charge only with its own supplied cable as they may have wired it in a non standard way. I've got a couple of things that are like that and they have warnings to that effect (only use the supplied cable for charging).

[Urbandreamer]

Buy branded USB/ HDMI/ Displayport cables, adapters et al and you should be ok with things being to official specification around power and data delivery.

Just watch out for kit that is USB C charge only with its own supplied cable as they may have wired it in a non standard way. I've got a couple of things that are like that and they have warnings to that effect (only use the supplied cable for charging).

Hell YES!

The PI3 (single board computer), doesn't even recognize the USB specs!.

Seriously, know what you are buying.

It's probably ok to fit some mad collection of cables to plug your toothbrush into a PI3 supply. Not such a good idea to do the same to plug a PI3 into your charger.

PS Display port is not Thunderbolt! Ok if you don't understand the point. However it's to point out that some USB-C ports are display port, while others are thunderbolt and yet others are for power. Cables are not so restrictive. IT'S NOT ABOUT USB-C!