Maybe its time to calibrate your battery..
Click here and download Battery Calibration app, then discharge your battery till your device turns itself off, then turn it on again and leave it until it turns itself again off. Then connect it to a charger and don't turn on 'till its charged to 100%. When charging finishes don't disconnect the charger and turn on the phone. Open Battery Calibration app and press Start Calibration and it will show you 2 methods first one is fast one and second method is full battery calibration method but to unlock that method it will tell you that you must watch a 30 second video, accept that and watch that video and when its finished exit the video ad and continue with calibration process. Wait 'till it finishes calibrating and when it finishes disconnect the charger and use your phone normally till it discharges again to that point that it turns itself off and when it turns itself off dont turn it on again and connect it to a charger till it charges to 100% again and then turn on your phone and see if your problem is still there. I hope its not and I hope that this method helped you! Cheers! 😉
