I moved from an iphone to the Z3C last year and couldn't be happier with the battery life. Today I upgraded to the new sony software up date. Lollipop 5.02. My phone is loosing power like never before. Lost 20% in 1 hour with normal usage. Do not upgrade your software. Just a fiasco. Waiting to see if there will be an update to fix but may have to move back to iphone.
I was facing the same issue with my Z3C after Lollipop upgrade. (1 and a half day battery life) Turn off adaptive brightness (Settings -> Display -> Adaptive brightness) as a workaround, and adjust the brightness manually. This is my 2nd day using my Z3C and my battery level is on 65%.
