Yesterday my battery life was very poor and this morning, after a wireless charger test, I left my fully charged phone off the charger for a couple of hours whilst I went back to bed. In two hours of inactivity, in flight mode no less, the battery level dropped by 17%. I then charged it again, made one change and in 6 hours of light use, it has only dropped by 19%.
The one change was to switch off "sync game requests" in games. Seems having a couple of games of AlphaJax and Draw something looking out for updates was killing the battery.