Why do USB-C to USB-C chargers charge quicker than USB-C to USB?

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Why do USB-C to USB-C chargers charge quicker than USB-C to USB?

In: Technology

Standard USB-A (the regular computer USB ports) only supports 5V, which is fine for charging a phone at maybe at most 10W, not much more than that, because it would require too much current through the thin wires

USB C on the other hand supports usb power delivery, when means devices can ask how much voltage they want and the charger (if supported) will give it to them, so it can deliver more power

I should also add that there are some quick chargers on USB A, but it’s not a USB protocol standard, it uses other protocols like quickcharge to deliver the right voltage to devices tagt support it

Just to get a bit of terminology clarified:

USB C is a physical convector standard, but often using using the wiring standard for USB 3, but not always

The ‘standard’ USB is a USB A connector.

USB 2 micro b, which is what was mostly used before USB C, usually output a max if 2.5 watts (5 volts at 0.5 amps).

Now the standard does allow for up to 60 watts, but that was rarely pushed through a mico connector. About the highest you commonly found was 15 watts (3 amps at 5 volts). Raspberry Pi’s use these.

USB C can put out up to 100 watts, and USB 3.1 USB A connector if setup for the USB battery charging specification can also due up to 100 watts.

Personally, I think USB naming setup is a mess right now. They introduced USB C, but also is 3, 3.1, 3.2 and IIRC 3.3 is on its way. But then they want to call them super speed and such instead of using .1,.2 etc.
Any cables/devices can use USB 3 over a USB C connector, but not always. My last phone (Samsung S8) supported fairly fast charging on a USB C connector, but only USB 2 data transfer speeds. And some USB C cables don’t support the full charging speed USB C can offer nor do some devices.

USB C can also be used for a Thunderbolt connector, but not always. USB C can also carry a display signal whether or not it’s a Thunderbolt cable, but won’t offer all the features of a display port over Thunderbolt.

For the time being you really need to look at what exactly the cable is rated for, because a USB C cables doesn’t garrantee USB C/USB 3 charring rates. It may be setup for USB 2. Hopefully the USB group that sets these standards gets there act together and irons out a lot of these wrinkles making it easier for consumers to understand. I’m a techie, and still had to look half this up because its a confusing mess!

The TLDR would be – if using a USB A to USB C cable, if the USB A end is blue or red it should be USB 3 or better, it should charge as fast as a C to C cable, assuming the charger supports that. Double check any product specs before ordering, and stay away from crappy knock off cables.