I recharge my Samsung Galaxy Tab S tablet, via a ‘normal’ Micro-USB cable, attached to a prescribed Samsung Fast Charger. What I have learned, is that we must be careful every time we insert the micro-jack into the device, to insert it only with gentle force and while keeping it straight.
If we fail to do that, we may damage the tiny contacts in the cable, or in the device.
At some point, during charging, the Tab S would show me a battery icon that had a red ‘X’ over it, instead of the usual icon, that has a black lightning-bolt over it. This red ‘X’ actually means, that we are only slow-charging, not fast-charging.
So what must have happened, because for a long time I was inserting the Micro-USB-Jack in a hasty, forceful way, was that I damaged the data pins, that a Samsung device will use to tell a Samsung charger, that it wants the 9V and not the 5V, for a fast charge.
I was able to solve this problem 100%, by replacing the charge cable. Hence, I was lucky, that most of the wear I had caused, seemed to affect the cable more than the socket in the device. It could have been the other way around.
This type of concern was also my reason, for getting a wireless charger for my phone, where I noticed that always to insert the tiny jack physically, could lead to problems one day. But in the case of my phone, I did not wait for erroneous behavior, before making this change.