A few points to clarify. In USB 2.0 and earlier, there are two kinds of hubs: self-powered and bus-powered. Self-powered hubs must provide 500 ma at each down

A few points to clarify. In USB 2.0 and earlier, there are two kinds of hubs: self-powered and bus-powered. Self-powered hubs must provide 500 ma at each downstream port. Bus-powered hubs must provide 100 ma at each downstream port. There are also two kinds of devices: high-power and low-power devices, meaning that they consume from their upstream port more than 100 ma or 100 ma or less, respectively. A bus-powered hub is a high-powered device, as from a port point of view, 500 ma can go down the cable to it (and devices connected to it). The maximum number of ports that a bus-powered hub can provide is 4 as 400 ma are required for each downstream port and the hub functionality uses some power. You cannot plug a bus-powered hub (a high power device as it can consume 500 ma from its upstream port) to a bus-powered hub. You can of course alternate between self- and bus-powered hubs. If the iPad can operate on 100 ma, then it can be connected to a bus-powered hub. If it requires more power, then it must be connected to a self-powered hub. Hope this helps. On a historical note, Apple has built systems that provide more than 500 ma from the root (the ports in the system itself). I am not an expert on if they still do. I'd hazard a guess the answer is yes.