Smoke Comes From Mi4 While Charging. Please Help Me

Dec 10, 2014
Hello, yesterday I charged my Mi4 with an external battery, I noticed that in the process both the phone and the battery were really hot.
When I came home after a long day the phone had no power so I plugged it in, after some seconds, smoke started to come out of the plug and it was going to burn soon, today I tryed plugging another battery to the phone, but this time it started to smoke and heating even faster.

What is the matter? do I have to change the charging port? or the battery? Is there any hope?

Please, I really need your help.

Thanks a lot for your support.