Why does my phone randomly shut off completely when it's no where near low battery?

[AC Question]

Every now and then at random times, my Samsung Galaxy Note 4 would, nearing 50% to 30%, would completely shut down. Sometimes it attempts to restart itself and power on, but would turn off again after the password screen appears. Also tried removing the battery and putting it back in, but never seems to work. Don't really know if it's one of the apps I've installed or any viruses I may have picked up, but sucks if I have to give up on this phone. Any answers on why this happens and how to fix it will be appreciated.

 

[B. Diddy]

Welcome to Android Central! The battery might be failing. Try a new or different battery.