Apple on Monday published a support document noting that some users who typically charge their iPod or iPhone via a USB 2.0 port on another gadget may not be able to do so with the iPad.
The reason? Simple: the iPad needs more juice than a 2.5-inch mobile device.
If you're used to charging your Apple devices with a USB power adapter, then nothing's much changed for you.
But if you're used to plugging your devices into an old MacBook or Windows system that uses USB 2.0, it may or may not work, depending on the age of the device.
Some USB 2.0 ports and accessories do not provide enough power to charge iPad. When this occurs the message "Not Charging" appears in the status bar next to the battery icon.
When attached to a computer with a standard, versus high-speed, USB port, the iPad will charge, but only when in sleep mode.