The note 4 is strangely sensitive to the battery. You cannot just use any battery. It needs to be new and high quality. I have an old real battery causing the phone to restart at 18% for no reason, and it would restart in a loop until I pulled out the battery. Note that even though it may say "Samsung" on the battery, it may not be a real one. You can tell most fakes by trying to use NFC. The NFC antenna is inside the battery, and most knock off batteries are low quality and do not include the NFC antenna.
This battery fixed my problem:
https://www.amazon.com/gp/product/B0193XB5OY/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1