Cheap, but good?

Let's start with the positives, this Power Bank provides about 9000mAh, in my view, enough promises close to the 10.000mAh the manufacturer.
The build quality is OK if not outstanding but for this low price can no longer be expected. The Aufladegeschwindigkeiten are OK, only the Power bank itself needs to 13h to be full again, which is quite long, but everything is still in the frame.

But why only 4 out of 5 *? The Power Bank has 2 USB ports. According to the manufacturer once 1A and 2.1A once. This is only partly true. Because both ports deliver in practice 1.7A + what is good in itself, but what happens when you load both ports with high-power devices?

The Power Bank turns, probably due to overload, from. On good German, the manufacturer says they please charge port with a 1A but you could weight more it yet, this can lead to an overload. But as I say, my terminal you may only xyz A consume? Right, that's not so easy.
Others do better manufacturers and it makes me doubt some of the electronics of this model.