100W of power over USB!?!



Posted by Trent Nouveau

The USB 3 Promoter group recently finalized a fresh spec for USB power delivery of up to 100W of juice.



According to Hexus, the new spec is sufficient to power both a laptop and external drives - devices which previously demanded their own external power source.

"Power direction is switchable so that, for example, an external battery could charge from a laptop USB port when it's connected to the mains but when the mains is disconnected that battery can be used to power the laptop," explained Mark Tyson of Hexus.  



The new spec is slated to go live some time in the not too distant future. Adoption will likely be slow initially due to an acute lack of supported peripheral and compatibility requirements on both sides of the connection cable. 

Fortunately, the new connection will be backwards compatible with USB 2.0 and 3.0, while power draw is "negotiated" to facilitate the safe charging and connection of low-power requirement peripherals. 



As SemiAccurate's Charlie Demerjian notes, the spec includes an intelligent check of both the cable and device capabilities. 



"With careful planning, not luck, there won't be any 'whoopsies' that involve smoke, flame, or other things that are funnier when they happen to someone else," said Demerjian.

"[Nevertheless], this allows [for] some very interesting possibilities, the most intriguing is getting rid of charging ports entirely, and having every USB por capable of powering the laptop. Or powering another laptop, monitor, or anything else. Or none of the above, and not catch fire while doing any of it - quite a trick when you are talking about pushing 100W over a thin USB cable."