Charging from a USB hub
MacFormat reported on a new product a few months ago but now I can't find the write-up about it. It was a short USB cable with a hub to bring USB ports to the front of the display, avoiding having to hunt for one at the back. Can it charge an iPhone and an iPad? Duke Zimmerman The drain from a Retina iPad is much higher than from an iPhone or non-Retina iPad. The best way to charge one is using the mains adaptor that came with it. You can also charge an iPad from the USB ports on a Mac or a Cinema or Thunderbolt Display, but there are some restrictions. The Mac or monitor must be on, not sleeping; it only works for one iPad at a time; and only from the ports on the back or on Apple’s wired keyboard.
Some hubs, like the the Belkin 4-port model available on Apple’s online store, can’t charge iPads. That requires a hub that can supply 2A of current. You could try the Anker nine-port USB 3.0 hub (£44 from Amazon), which has one 2.1A charging port for your iPad. It’s a powered hub, so you’ll need to plug it into the wall as well as the back of your monitor.