It has to "negotiate", insofar as if you connect a cable between devices, if they fail to "negotiate", then nothing happens.
This differs from earlier USB standards which always guaranteed 5V1A. I.e. the expectation that plugging a cable in, would result in something "working".
Might sound trivial but imagine you needed your phone to get help, but phone is dead, you plug battery pack in and.. (edited)
Actually no, there are many iterations of the USB protocol. There was never a 5v @ 1A guarantee... USB was also never designed as a power delivery mechanism. (This is why other peripheral technologies, such as FireWire where created. At the time it was superior to USB, however it's cost and the newer iterations of USB is what killed it off.) The USB 2.0 specification allows Hosts to deliver 5V at 500 mA, for a total power output of 2.5 watts. USB 3.0 and 3.1 allow 5V at 900 mA (4.5W). Certified Hosts and Devices must limit their power delivery and consumption to these "default" power levels. The negotiation is what determines different power outputs - this is where a lot of manufacturers went off spec as they couldn't agree on what the different outputs should be. Also it is not necessary for USB-C compliant devices to implement USB Power Delivery, if no negotiation takes place then the default output will be 5v @ 500mA, this is by design.
Absolutely nonsense article, which is not surprising as howtogeek is well known to publish inaccurate stuff just to earn fees from the referal links of the magical alternatives they provide.
I just read that article as it is full of misinformation. Early phone models that sported a USB port did not accept power via the USB port - the phone would have a separate dedicated charger & charge port. When manufacturers realised they could use the USB port for data & power they used a dedicated USB chip which provided protection from defective cables. Whilst it's not impossible to cause a fire with a damaged USB cable the chances of the fault coming from an issue with the phone is very unlikely. Most faults are due to manufacturers ignoring the USB spec. This article appears to be scaremongering to convince the reader to purchase Amazon cables, especially when all the links are affiliate links...
Thanks, the links to Amazon are useful for when I need a new usb c.
Author
What no links for Argos or AliExpress
It reads like either a writer who knows little about USB or an auto generated article, lots of suspicious statements in that text. (edited)
Author
Well it is from a "geek" website!
Howtogeek, this is where the Verge goes to learn how to build PCs.
18 Comments
sorted byIt has to "negotiate", insofar as if you connect a cable between devices, if they fail to "negotiate", then nothing happens.
This differs from earlier USB standards which always guaranteed 5V1A. I.e. the expectation that plugging a cable in, would result in something "working".
Might sound trivial but imagine you needed your phone to get help, but phone is dead, you plug battery pack in and.. (edited)
USB was also never designed as a power delivery mechanism. (This is why other peripheral technologies, such as FireWire where created. At the time it was superior to USB, however it's cost and the newer iterations of USB is what killed it off.)
The USB 2.0 specification allows Hosts to deliver 5V at 500 mA, for a total power output of 2.5 watts. USB 3.0 and 3.1 allow 5V at 900 mA (4.5W). Certified Hosts and Devices must limit their power delivery and consumption to these "default" power levels.
The negotiation is what determines different power outputs - this is where a lot of manufacturers went off spec as they couldn't agree on what the different outputs should be.
Also it is not necessary for USB-C compliant devices to implement USB Power Delivery, if no negotiation takes place then the default output will be 5v @ 500mA, this is by design.
This article appears to be scaremongering to convince the reader to purchase Amazon cables, especially when all the links are affiliate links...