My I phone 5s, ios 9.0.2 - battery die fast. Its life is only less than 5 hours. what could be the reason and how can i rectify this?

Basics from the manual are restart, reset, restore from backup, restore as new.

I suggest you log an incident call with Apple.

i have the same problem, iphone 5s with 9.0.2 and the battery went from 20% to 3 % right in front of my eye while using it!

Logged the call and ask to restore 9.0.2 which I did but today its still draining to fast and jumps, so for example was at 45% for ages while using it. stopped using it a few minutes then picked it up and it went to 33%.

I think there is something wrong with the algorithm that they have used in the 5S, that or the a/d converters that work out the battery volts has a glitch with the new software.

I down graded to 8.4.1 and it worked fine, but now I tried 9.0.2 again the fault is back and now I can't downgrade as apple have stopped singing it.

I'm due a call back today from apple support to see if it is fixed so will be telling them NO its not.

how can I restore? using the itunes? what if Apple already stopped from signing in the ios8.4.1? What will I do?