Hi folks, here is a HTC One X back case with battery. The back case does not only serve you back cover, it also charge your One X with a simple click. Unlike those portable charger, this one comes wireless.
HTC One X Power Bank, has 3.7v 2200 mAh battery. It is powerful enough to give you twice using time.
For less than MYR 100 (USD 35), it is a good bargain.