FastMac’s TruePower iV is a must have for any iPhone user who needs to stay fully charged all day without being able to plug in.

I had an opportunity to see just how well it works on my trip home from Macworld Expo. I charged my iV overnight before I left, and after more than 8 hours of travel time, including more than 4 hours of music, 1 hour of video, and several games of Frenzic & reMovem, my iPhone was still fully charged and the iV’s battery indicator still showed 4 lights. Normally after such a trip, I’d find my iPhone nearly out of power by the time I got home.

The iV adds a bit of bulk and not too much weight to the iPhone, but it can still be carried comfortably in a coat pocket. I prefer the iV’s form factor, which cradles the iPhone, to that of Richard Solo’s battery which hangs off the bottom of the iPhone.

The iV provides 3100 mAh of battery power (vs. 1800 for Richard Solo’s battery). FastMac claims up to 24 hours of talk time, 72 hours of audio playback, up to 21 hours of video playback, and up to 30 days of standby time. Based on my experience traveling home from Macworld, I think that’s probably accurate.

The iV features a standard iPhone/iPod docking connector for charging and even fits in a dock. In addition to powering an iPhone, it also features an extra USB port to charge other devices and an extremely bright LED flashlight for emergency use or low light photos.

I highly recommend the TruePower iV. I’ll never take another trip without it.