I'm not using this phone every day, so I can't really say; however, I did not notice any battery drain. With a ROM from xiaomi.eu, I experienced a 10% / hour consume; with this one, it's 1% / hour. It's still more than with the original ROM. I charged my phone 14 days ago, there is 56% battery left : I turn it on once or twice a week to check and update it.