Has been encountering higher battery drainage that usual on your iPhone or iPad? Apparently the problem was from Facebook app. An engineer from Facebook, Ari Grant has admitted the app has been using up more battery due to series of bugs including one that ate up extra CPU cycles.
The first issue that they call it “CPU spin” which repeated process in background thus it uses more power than usual. The second issue was the audio management session, where the Facebook app leave the audio session stays open running silent in background.
Good news is that, they have rectify these problems and will be releasing a new update later today
Source: Tech Crunch