Question ZAGGsparq 2.0 + HTC desire

Has anyone tried Zaggsparq 2.0 and desire compatibility. I am not aware of usb power requirements for desire?whether zagg supplies high/low/right amps. But I am sure many of you must know minor details about htc desire. I am going to buy it, if someone can posts any suggestion, and later I can provide back feedback for others that might be interested to buy.