Neil Hughes, writing for Apple Insider:

Buried within the hardware regulatory information for the iPad Pro, it’s revealed that the 12.9-inch tablet can use 14.5 volts at 2 amps, which is equivalent to 29 watts. However, the iPad Pro only ships with a 12-watt power adapter.

Apple already ships a 29-watt power adapter with its 12-inch MacBook with Retina display, but the thin-and-light notebook charges over a more capable USB 3 cable with a USB-C port.

The Lightning cable that ships with the iPad Pro, however, is limited to a load of 12 watts, and it features a full-size USB Type-A 2.0 port on the opposite end, not a USB-C connector.

Currently, there is no way to directly charge an iPad Pro with Apple’s 29-watt MacBook power adapter. That’s because there aren’t yet any sanctioned USB 3 Lightning cables available on the market.

Interesting.