Does A USB 3.0 cable carry more power than a USB 2.0?

[I am an SSD]

title^ 

 

If yes, when I plug my fast charge enabled phone into my usb 3 port on my PC , i should be able to  charge it faster, yes?

[spartaman64]

yes and no i found many devices dont actually charge faster on usb 3 even though its capable of charging faster

[Bsmith]

on title, yes.

 

on other question, I don't exactly know, might depend on your phone not all of them handle higher voltage/wattage.

[mariushm]

The cable itself is a "dumb" thing, it's just a bunch of wires with connectors at both ends.

 

The guys that invented USB place some restrictions on how much power can be transferred through usb cables, but these restrictions are basically just to make sure a device doesn't damage the cable by drawing too much current through a cable with very thin wires.

Basically the guys that made the USB standard said that no matter what they're made of or how they look (round or flat) , usb 2.0 cables must be able to safely transfer 5v at 0.5A , or 2.5 watts.

All but the cheapest cables out there have wires thick enough that in reality it's safe to transfer even 1A or 1.5A at 5v through these usb 2.0 cables.

 

USB ports on computers are usually not artificially limited to 0.5A as the standard says. Usually, up to 4 ports in the back of your computer are connected to a  "power supply" on the motherboard which has a protection configured to disconnect the ports if more than 2A is consumed.

So, if you plug a device into the back of such a connector, there's nothing artificially limiting the device from consuming more than 0.5A from the computer.

 

In the USB 3 standard, the guys scratched their heads and said it would be a good idea to recommend bigger minimum values, so they say all cables must be made with wires thick enough to support at least 5v at 0.9A or about 4.5 watts.  This is a sort of basic mode, a compatibility mode with usb 2.0, because usb 3 has a more complex power delivery mechanism which is practically not used at all in computers or other devices yet.

 

If the usb controller (the one to which the usb 3 jacks are connected to) supports it, in theory the device (phone, video camera etc)  can communicate with the usb 3 controller and tell it that instead of 5v it can send 12v through the wires, or even 20v ... the device and controller can negociate voltage and maximum current up to 100 watts and in the standard there's a way for the usb 3 cable to tell the usb 3 controller exactly how much power it can safely transfer (for example it may only be able to transfer up to 12v at 4A or in other words 50 watts so if a video camera says "I want 20v at 5a to quick charge the bad ass battery" the controller could say tough luck, all i can do is 12v at up to 4a, take it or leave it)

 

Anyway, short version, just like with usb 2 cables, usb 3 cables can carry more current than what the usb standard says, but it's up to the device itself (the phone, the camera, the laptop, the gameboy etc) to have a chip smart enough inside to figure it can suck more than the minimum current.  Just chaning the cable or plugging it in another connector won't do much.

 

PS.  Phone chargers and battery chargers are a special case, because knowing the phone isn't going to transfer or receive data through the usb cable, they use some tricks with the two data wires inside the usb cable to let the chip inside the phone that's taking care of battery charging know it's ok to transfer more than 0.5a or 0.9a of power through the cable. Changing the cable won't do anything, the charger has to tell the phone through those data wires where's the maximum limit - if for example you'd connect the cable into a usb port on your computer, the computer won't know to send those commands through the data wires to tell the charging chip it's ok to draw more than what's recommended.

 

[BrightCandle]

One of the ways this detection for higher AMPS works is via resistors in the cables. Something to be careful of is that a lot of USB 2.0 to 3.0 cables especially have resistors claiming they can provide more power than they should and it can damage USB 2.0 ports that aren't designed for high current draw. USB 3.0 Type C connectors can go up to 2.5A but it requires getting all the elements correct, fast charging remains a bit hit and miss with USB 3.0 in my experience. I have a 3.0 hub that is powered and can in theory provide full power to my Nexus 5X phone but in practice the Type A to Type C 3.0 cable isn't allowing more than about 1A instead of the 2.5A I can get from the provided charger.

[I am an SSD]

On 7/12/2016 at 8:24 PM, mariushm said:

snip

 

Thank you for taking the time   

[dtaflorida]

On 7/12/2016 at 9:54 AM, mariushm said:

it's just a bunch of wires with connectors at both ends

Sorta true, but there's something important you left out. The gauge of the wires. 

 

http://lifehacker.com/cables-can-significantly-impact-the-charging-speed-of-y-1532784722

 

I have a coworker that buys cheap cables and complains about how his devices charge so slow. He get those big multipacks that are like $5~10 for 10+ cables.