as ive been trying to say the whole issue with my lumia 640 not xl after two days I left it in a window as it got to hot when I came back it said on the display overheated and needs to power off but it did not power off as it detected instead it stayed on until user input, after this it was all over for the battery, I then took another battery from same type of phone and all was well again as if it never happened, as ive said there is a sensor overheating detection device on most batteries today for smart phones. once they are triggered it seems inpossible to fix without buying new, as youtube will show how to bypass this sensor it will not work with lumia 640's the battery is sealed in a way that will destroy it trying to solve it, also the charge port is normal with that high raised center on the port its normal and Is for a tighter fitting charge wire,..