I have a strange problem when charging my S5 . I'm using a 3rd party charging pad with card receiver behind battery door. The phone needs to be placed quite accurately on the pad for it to start charging, wireless pop up screen appears and everything seems OK. However, the phone and pad both appear to get quite hot and i've noticed that after a period of time it enters a loop where the wireless charging screen pops up and bleeps, as if you had just placed the phone down. Unless you reposition the phone this keeps happening, not good when charging over night. Could anyone throw some light on this problem ?