I got it in November about a month ago and it's never been great. I've blocked all the background apps except weather flow, uninstalled the skype beta and Nokia drive, and wifi, bluetooth, NFC are all off. One gmail account set to push.
It feels a bit daft as I can't use the phone as I'd like to for fear of killing the battery - Ideally I'd be able to keep wifi on (although I'm used to managing that fro my iphone), do a bit of gaming and have say four or five live tiles pulling in data. Is there any way to somehow conclusively test whether or not the battery in this unit is faulty? The thing that makes me think that it could be software is that sometimes with medium use I get a 14 hour day (which is still on the low side but much better than six!)