You asked for it now here it is, part two of our iPhone 4 battery case review featuring fan-fave Exolife from Exogear. Like the Mophie Juice Pack Air and Mili PowerSpring 4 battery packs we already reviewed, the Exolife case promises to "virtually double" the life of your iPhone 4 -- something neither the Mophie nor Mili could quite pull off. Exogear's claim is even more bold given its additional boast about being the "world's thinnest and lightest battery case" for the iPhone 4. Can it possibly compete and knock the Mophie Juice Pack Air out of its title position? Click through to find out.Galler