Mili iPhone Case with Battery
The Mili Powerspring offers protection and extra energy for your iPhone 4. With a capacity of 1600mAh it gives you an extra 6 hours of talk time. The charging time of the integrated battery is 4 hours and all in all it doesn’t look too bad, does it? Aprx. 85 US-Dollars. Or maybe you prefer the juice pack air by Mophie?