I have gone a full month of folloing Sony's recommended  solution to this problem - "Just wait for it to start working". Time Frame: Daily for 30 days Conditions: Commence charging between 9:00 and 9:30pm. End charging between 7:00 am and 7:30am No incidental charging during the day No changes to the settings of Battery Care - remains on constantly. Test Results: Battery Care detects regular usage and commences regulating charges: FAIL Any indication that Battery Care was functioning in any way (Notifications etc): FAIL Additional observations: As previously stated, during this test my battery life degraded significantly. On the last day of the period the battery warning of 15% came at about 5pm and I was forced to leave the phone unused (no screen, audio, bluetooth or messages) in order to make it to 9:00pm. When I put it on charge it was at 2%. Conclusion: On my specific phone, Battery Care does not function as intended. The continued overnight charging as recommended by the community and Sony Representitives not only does not solve the problem, but has a severe negative effect on the battery life.   ... View more

The day I previously posted I started a 1 month trial of Battery Care.  I stopped my normal routine of turning B.C. off and on every night to reset it. ( i've previously tried for a week or so to get it work after stopping but gave up before success). My usage is very regular. On charge between 9:00 - 9:30pm and off charge between 7:00 and 7:30 and I have made sure to stick rigidly to that routine this month.  I think that should be enough of a routine for B.C. to pick up on. I am now 3 weeks into this trial. Battery care has not started working yet My battery life has reduced drastically. At the beginning of the trial I ended the day at about 40% (down from 50-55% when the phone was newer) Now I finish the day on 12-15% Its not looking good so far. I'll post again next week.   ... View more

I notice all the comments are a combination of: a) I have the same problem, the tech doesn't work b) just trust in the tech, it will work itself out eventually c) I want manual control   Sony, are you listening? ... View more

Same problem here on XA2. I have tried 3 times to go for a week without touching the setting and it won't pick up my habbits even though i start charging in a half hour window each night and take it off charge in a 5 minute window in the morning.   I just switch it off and on each night and it always seems to select [Time taken off charge yesterday] - 1 hour i.e. I always take it off at around 7am and it almost always choses 6am as the finish time.   I don't use an alarm (on my phone) to wake up so i'd like to just set the time manually. ... View more

I am also having the fast battery drain problem on 2x Xperia Z1 Compact phones.   I followed the recommend fix and installed PC Companion.  It says I have the most up to date software. I selected Repair my Phone. "Problem: There is no software available for your device"  at the bottom of the page it says "If you still encounter problems, please report issues to Sony Mobile (opens in a new window) and provide the error above.   Clicking on the link goes HERE but the Xperia Z1 Compact is not listed any more.   I fiddled about a bit more and found THIS PAGE for the Z1 Compact that lists: Android version: Android 5.1 (Lollipop) Latest available software: 14.6.A.0.368 Release started: 2015-09-14 However I am running 5.1.1  14.6.A.1.216 that I got from an OTA update.   So has Sony removed the faulty update but not admited that its a problem or provided a fix?!?!   ... View more