USB Power Delivery’s Big Upgrade Gets Us Closer to One Cable to Rule Them All

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Oct 9, 2016
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For people who can’t stand proprietary power cables, USB Power Delivery just got a big upgrade that raises the limit on the max power transfer from 100 watts all the way up to 240 watts.

The latest update to USB’s capabilities comes from USB-IF, which recently released revision 2.1 of the USB Type-C Cable and Connector Specification. For version 2.1, the big change is that the USB-IF is increasing the max power limit for USB Power Delivery from 100 watts to 240 watts, which should give USB-PD enough juice to charge all but the beefiest laptops without the need for a proprietary power adapter.

Specifically, the USB-IF calls USB-PD’s support for transferring 100 to 240 watts of electricity “Extended Power Range” or EPR, with the main requirement being that the cable can handle five amps of power at up to 48 volts (5 x 48 = 240). And as with previous USB specs, USB-C cables that support EPR’s new higher power limits should be backward compatible with existing USB-PD devices—both phones and laptops.

Unfortunately, if you want to take advantage of USB-PD’s new capabilities, you will need to buy new cables (or at least wait for laptop makers to include them in the box), as current USB-PD cords are only rated to handle up to 100 watts of power. On the bright side, the USB-IF has also mandated that USB-C cables that support EPR should be “visibly identified with EPR cable identification items,” which should help eliminate any confusion when trying to figure out which cables you need.

Here’s a table showing the power transfer capabilities of different types of USB specs, including the new USB-PD EPR at the bottom.Screenshot: USB-IF


In the end, the big impact is that by raising the limit for USB-PD to 240 watts, it should become much easier to make bigger and more powerful laptops that don’t require proprietary power cables. Typically, most new 13- and 14-inch laptops, like the XPS 13, require less than 100 watts of power, which made it easy for device makers to include support for charging over USB-PD.

However, when it comes to larger 15-inch and 17-inch notebooks—especially gaming laptops—their higher power draw often forces device makers to equip their systems with propriety power bricks. And even for bigger systems that did support the previous iteration of USB-PD like MSI’s Stealth 15m, because the system’s total power draw tops out at 150 watts, that means charging via USB-PD is slower than with MSI’s proprietary charger, with the Stealth 15m still requiring juice from its battery to power the system when charging via USB-PD under full load.

That said, even with a new limit of 240 watts, there will still be a handful of big mobile workstations or desktop replacement laptops that need more juice than USB-PD with EPR can safely deliver. But for smaller systems, USB-PD with EPR means we’re getting even closer to the dream of having one cable and connector that works with everything.

 
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