USB 3.0, the most recent version of the USB data/power specification, currently offers much faster transfer speeds than USB 2.0. Compatible devices get speeds up to 5Gbps, and soon may see power transfer rates of up to 100 watts.
The USB 3.0 spec is still evolving, and recently the group of companies responsible for it announced new details about USB charging with this generation port and cables. USB 2.0 delivers 2.5 Watts of power to devices, which is enough to charge smartphones and other small electronics. Current USB 3.0 cables up the juice to 4.5 Watts.
The newly announced standard will offer six profiles and deliver different amounts of power depending on a device’s needs via new, intelligent cables that will need “USB Power Delivery” certification. Profiles range from as low as 5V/2A all the way up to 100 Watt power at 12V or 20V and 5A — enough to power a laptop.
This could mean the end of proprietary A/C adapters and having to shell out ridiculous money for replacement power cords if yours is lost or damaged. It also means less cords to carry around, especially on long trips. If you can use the same cord to charge both laptop, smartphone, tablet and eReader, why bring four of them? (I usually travel with one USB cord to every two devices that need it.)
This new USB 3.0 spec is available to manufacturers for implementation right now, but it will likely be several quarters before we see a USB-powered laptop. Considering how long it’s taken USB 3.0 to finally become a feature we can expect to see even on low-end laptops (the technology was introduced back in 2008), wide adoption could take a while.
via TechWeek Europe