Anker PowerCore Edge
Conclusion: highly recommended!
Highest quality, all described well, customer service with German landline number (Frankfurt am Main), with flat rate calls are free.
The reviews in the internet are all very well. For the first battery charging I had no charger from Anker, so I had used the USB charger of my BlackBerry. At 9 o'clock am in the morning the battery was charged about 75% (it has 4 LEDs only, three of them illuminated by briefly pressing the Status button). The next battery charges I do most time with the 36 W 5 V / 7.2 A 4-Port USB Charger by Anker.
But for charging overnight, every 5 Watt USB charger is perfect! Slow charging is smoother for the battery! Use only high quality cables!
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