Technology
I tested the unit with a new 5s, ie. the battery capacity of the iPhone was still full brand-new performance.
The spare battery invited the iPhone once from 0 to 100%. 3 days later, the iPhone was at 20%, could again be recharged to 49%, or about 130% Nachladekapazität. Mathematically, there would be more, but provides the sheath 3000 mAh, a new iPhone 5s 1570 mAh (in older devices, the performance already be as low as 1400 to 1300 mAh). Reason is the noticeable warming in the charging process be: The iPhone is charged very quickly, almost like at the outlet. The heating then corresponds certainly the loss of capacity.
A small, but certainly for many practical detail: The charging port of the battery cover is designed as a micro-USB, the part can thus serve as the same adapter, if you take has no Ligtning cable from the package.
Operation / handling
The iPhone uses the shell noticeably bacon on, the inside pocket of the jacket is clearly bulged, the weight doubles felt. For this you need at the airport do not like a junkie to the next outlet and rushing during the transfer time squatting on a concrete base, which I call Deal.
The charging function can be switched on and off, so you have to control how much power you want to keep to what battery - convenient if you share the shell.
The release button is a bit fiddly, more delicate fingers than my but will help many users. This small adapter cable for the headphone jack I call "thought along" - for my headphones not necessary, but there are definitely models whose plug would thwart a use with shell.
Conclusion
Does what it is supposed that. Attractively and without frustration factor How fast or slow optics and battery will reduce the use of days, I could not test. Compared to solutions with a separate spare battery less Frick celled alternative because a cable is saved only one device needs to be carried. A recommendation for long walks or air travel.
