In the message that I posted I tried to break this down into potential issues. Numbering them.
In relation to #3 you do not add anything. Unless the charger has an output of about 2.4A at 5V the S3 will charge very slowly. Leaving it off or in sleep mode it will charge even if it reports that it is not.
Thus my Mu UK plug folding tablet charger (you need a magnifying glass to read the tiny print) outputs as above. My Aukey Model PA12 (EU 2 pin plug) through the two Air Power ports also outputs 2.4A at 5V. Both work just fine all the time. However, my UK
wall socket at 2A does not and that sometimes shows charge and sometimes not. However, it is actually charging. Just slowly. As I wrote, the icon status is misleading. See point
#5.
In relation to point #4 and cables you are, bluntly, wrong if you are implying that the cable does not make a difference. The AWG of the cable used will throttle the charge irrespective of the output if it is inadequate.
Others have written about this and they are correct.
Now, what would interest me is if any of you out there can assist with the following related point: the Aukey Model PA12 has a third USB output which is
Quick Charge 2.0. The rating for that (you need a torch as well as a magnifying glass to even see the print on the side of the unit) is
5V/2A, 9V/2A, 12V/1.5A and 10W/18W (Max). The instructions for the unit state in the FAQ:-
Can I use the quick charge port to charge my devices which do not have Quick Charge tech?
A: Yes. You can use the charger to charge any devices with 5V/9V/12V output. However, the charging speed will not be as fast as the Quick Charge tech compatible devices.
Out of prudence, or cowardice, I have not used the Quick Charge port with the S3. Does anyone with technical expertise have knowledge of the position?
a. Is the S3 Quick Charge 2.0 enabled? The Qualcomm site would indicate not?
b. Either way, is it safe to use the Quick Charge Port with the S3?
c. If it is safe, would there be any advantage in doing so?