This is my first time going on here. I wondered if anyone knows why S4 mini seems to run out of battery very quickly when not in use. I keep searching on line and can go into running applications and stop them one by one but don't want to keep doing this. This is my partner's phone and she hardly uses it but it just keeps running down overnight. It seems that something keeps firing itself up in the background but I don't know what is doing it. It may be linked to updates starting apps but what app is causing the problem? Any suggestions greatly appreciated.