I bought this item earlier 2011. It's been a life saver in many situations especially when I traveled. I am using this device for smart phones that I also use it as MP3 player, video player, GPS on the road, WIFI hotspot to share data with my tablet...etc. The tiny internal phone battery just won't last for a few hours. With IMP500 huge 5000mah capacity, I don't need to get near a computer or AC outlet for a few days on a trip.