For testing purposes, we got the Wicked Chili Pro Series PSU - Ultra Slim - USB adapter for Apple iPhone 6/6 / 5C / 5S / 5 / 4S / 4 / 3GS, iPod Nano / Touch / Shuffle - Travel Charger Adapter for socket (1000mA , 100-240V, white / white) of testberichte.reviews provided. The solidly manufactured PSU does what it should do invites all to connect with it via USB cable). It comes with a manual in English and German supplied with all the usual warnings, technical data, etc .. The small power pack can be neatly stowed away and take anywhere and fits thanks to Euro - plug in Europe actually in all outlets. The charges will take just as long as with the respective original power supplies and the power supply is not overly warm during charging. During charging, a simultaneous usage of connected devices is possible to have no wobbles or connection problems.
CONCLUSION: It's always good to have multiple sources of power, so you always have one at hand. Therefore, as second or third power supply has a strong buy recommendation from me.