The Xiaomi 16000mAH power bank, using its original USB cable, didn't work on my Z3. Though, to my surprise, it worked on other smartphones (have tried samsung and lenovo). So I tried my friend's power bank USB cable albeit blindly (since the Xiaomi unit worked with other phones, there should be no problem with the cable right?), and strangely, it worked!
So what gives? Later on, I found out that the other cable is a "Charge-only" cable (cannot use for data transfer).
So why do you think exactly does this Xiaomi 16000mAH needs a charge-only USB cable in order to work with Z3 but not with other device? Also, do you think it safe to use it that way in the long run?
Lastly find it strange that I cannot seem to find (I mean Google) any case similar to mine (I don't think I'm the only Z3 user who purchased this power bank), but I also think it is genuine (from these: https://www.youtube.com/watch?v=obYhTgzEVP8; https://www.techmesto.com/identify-fake-xiaomi-power-bank/) I've already contacted the supplier about these, I think I can still send it back, but I really had it on a good deal (from Malaysia, below $25, including everything, if converted).
What do you think?