The battery issues and the increase in data usage issues

I love your detailed analysis.

 

I'd say yes - probably.

I read somewhere (can't find it now ) that it has been discovered that under iOS5 the phone still uses 3G (for some things at least) even when it's connected to Wi-Fi.

I guess this would explain increased battery usage, and it would explain something that happened to me...

I was out of the country the other weekend so using Roaming Data. My plan includes 25MB Roaming Data per day. At ~6pm I got a text from Vodafone saying I was nearing my limit (I think they send them when you hit 80%) so I reduced the amount I was using the phone (was using Maps a lot). An hour later I was back on the Wi-Fi at the hotel, and stayed connected to that until we went out the following morning.

Just before midnight I got another text saying I had gone over the 25MB by 3MB - WTF

So, it seems like my phone was using 3G even when it was on Wi-Fi. Coincidently (or not) this was around the time my battery usage went bad. Up until then I'd been getting excellent usage.

 

And if you cared to read further, you'd also "discover" that previous iPhone models have done this as well under certain circumstances (such as when sleeping).

But there's a pretty easy way to find out if the battery and data usage issues are related...



Do this, and see if battery life improves. If it doesn't, then turn off "Documents & Data" and see if there's a change.