mi3 terrible battery life..

Aug 22, 2014
Hi I recently bought a new mi3 and I'm with the latest Dev ROM but I'm facing terrible battery life while idling .. I just lost 3% in one hour without doing anything .. Just plug off the charger and idling for one hour .. Location .. Sync is off and I have no app that could battery drain because it's exactly the same app I used to have in my old device where battery life was OK .. Is it because the last Dev ROM ? Or is it because mi3 have terrible battery life in general ?