The perfect Power Bank!

Electronics
Just measured it - the voltage monitoring holds - both during charging of the internal battery and during operation - the example provided by the manufacturers Liion voltage range of 2.5V to 4.2V reliably - the prerequisite for a long life of the internal battery.
The signaling capacity on the LED is done reliably. Bit dark, but you can see it still.
Important: With combined USB data / charging cable, most connected devices approve only 500 mA. So you want instead of the supplied use a separate USB cable, then care should be taken to a "real" charging cable, z. B. Speedlink Pecos Spiral Micro USB Charging Cable.

internal battery
The supplied has not particularly convinced me why a Panasonic NCR88650B came in with 3400 mAh of battery parts de. In my eyes, one of the biggest advantages of lemik Power Bank: Replaceable battery! Future versions use (eg NCR18650G with 3600 mAh), take several charged batteries and replace the road.

Housing
They're unique! High quality robust stainless steel instead of plastic. Noble finish. Nice gift idea :-)