Battery life and iOS updates

[Applerx]

Hi,

I don't know if this has been asked before, I couldn't find anything...

Whenever I install a new iOS update, battery life on my iPhone 6 is fantastic. Even with quite heavy usage I still have 30-40% left at the end of the day. But that changes over time. After just a few weeks, the battery will drain a lot faster and I need to charge the phone much earlier.

This always happens after a few weeks but is temporarily fixed when a new iOS version is released.
It was the case with 8.3 -> 8.4, 8.4 -> 8.4.1, 8.4.1 -> 9.0 and so on.

It don't change any settings (background activities etc) that could decrease battery time nor did I install a ton of new apps.

Any ideas what the problem might be?

 

[JamesMB]

When you monitor Settings/Battery, what does that tell you?

 

[Applerx]

Haven't really monitored battery yet, at least Icouldn't find anything unusual.

I updated to iOS 9.2 Beta 3 two days ago and everything is fine now: 6h12m usage and 15h28m standby with 27% remaining.

Before the update that would not have been possible.

I will keep monitoring but I'm sure battery life will decrease in about a week or so...

 

[JamesMB]

When you do an IOS update, all of your apps get reset/closed, so it is gonna be up to you to monitor your battery usage and see what is happening. If you click on any entry in that screen, it will give you much more useful information, i.e., what is running in the background.