Most USB syncing hubs do not charge devices at more than a trickle rate while syncing. A recent firmware enhancement for our customers permitted them to update their Cambrionix-based (PP and U series) USB hubs to add a valuable feature: the ability to charge while iPads and other devices are in sync mode.
Some devices (including Apple devices with Lightning connectors and certain others such as Google Nexus 7 and 10, etc.), have the ability to sync and charge at a power setting that is higher than the normal USB 2.0 sync rate of 500mA. This allows our hubs to provide a charge rate of approximately 1.5A in sync mode.
This permits you, under some circumstances, to fully charge devices while they are left in sync mode, something that is not possible with conventional sync-charge systems. If you are using devices that can take advantage of this, you can leave your devices connected to a host and still charge them overnight. If the devices are not in active use with displays on full, playing videos, etc., they will go from depleted to charged with this feature.
Will the screen display that the iPads are charging? Yes. iPads equipped with Lightning cables will display that they are charging in this mode. Other devices might not. It depends on the device.