As a college kid I am constantly on the go and my iPhone's battery takes a beating. For christmas I received this portable battery and it has already saved me on numerous occasions. It is great how small it is as I can put it in my pocket or can quickly charge my phone up in one of my backpack pockets. It is really quick and am amazed at how I can charge my phone up twice on it. It does take a long to charge the battery pack but what I recommend is to charge it overnight along side your phone. I charge it on a dual usb hub with my iPhone so when I leave in the morning I can grab both without forgetting one or the other. It is a great product that I highly recommend and many people have been impressed with its abilities. Looking forward to more from this company!