Even if I just want a device that supports the 2.1A USB charge mode, load, this is not supported by this adapter or loaded sufficiently quickly. My Tablet (Dell Venue 8 Pro) quasi not load and a current phone (Alcatel 6043d) if loaded very slowly at all (depending on battery condition) :-(. When I recently visited, the adapter has been tried with several devices - the same result, newer devices are quasi nichtz loaded or only very slowly.
Just for the record, I've used in the experiments always the same USB / charging cable (30cm) and repeatedly gegengecheckt against a functioning adapter (2.1A)! I have also always tried both ports of the adapter and when using both USB ports, no improvement has also shown (was expected).
Well, I thought, just a defect - so a second adapter ordered but again exactly the same thing !!!
The adapter makes it basically a very good impression (the packaging), but the shockproof connection looks further than "other" adapter from the wall socket - this is he plugged something wacklicher.
The blue LED between the two USB ports permanently lit, it is virtually a ready indicator, and is relatively light - I would accordingly not recommend adapters for the bedroom, unless you want a night light ;-).
No idea why the Rezesionen to the adapter are mostly positive (for me the reason to buy), as an electrical engineer, I have a rough understanding of the matter, but this adapter I was at my wits and the attempts of the "fault isolation" at the end.
Both adapters go back ...