You may not have noticed, but the Facebook app for iPhone and iPad apparently is using more battery than it should. This came to light as Facebook Engineer Ari Grant has admitted a couple of battery related issues but he assures that a fix is on its way.
There are 2 reasons why this is happening. The first issues is what he calls as a CPU Spin within their network code. Basically it is a repeated process in the background which uses more power than usual. The second problem is how the Facebook app handles audio playback. If you leave Facebook after watching a video, the audio is muted but the session is still active in the background. While it appears that nothing is happening, it continues to consume power in the background.
Ari Grant had also assured that the battery issue is not caused by their optional Location history feature. For those who didn’t enable this feature, Facebook isn’t accessing your location in the background without your consent. The good news is that a new Facebook App update addressing these problems will be released later today.
[ SOURCE ]