Manufacturer promises up to 80 percent longer run time when it comes to Mophie Juice Pack Helium External battery case for iPhone 5.

Many current smartphones feature a tightly integrated battery. That may be technically feasible design. For users who use their mobile phone more intensely, this can meant in doubt, each to stand in the afternoon with an empty iPhone 5 battery - and that in the absence of ability to simply replace the power source for the smartphone.

From different manufacture...