Why does my battery drain 2% a minute?

[Michelle Sin]

I've had my phone for about a year now oneplus one and recently it drains so much wether I'm using it or not. Last night while I was sleeping my battery w at 70 toys even I woke up it was dead. Is there anything I can do?

 

[Golfdriver97]

Welcome to the forums. Have you had any systems updates installed recently? Have you done a reset?