Snippet: Facebook App is Draining iPhone Battery ☇

Sebastian Duvel recently discovered the Facebook app was causing his iPhone 4S’s battery to drain quite a bit faster than normal. He reviews iPhone multitasking, and explains some of the tests he’s conducted:

The last few weeks my beloved iPhone 4S lost battery extremely fast. After a normal work day there was hardly 10% left. That means after 12 hours and little usage of the iPhone.

So I went on to find the cause. As an iOS developer I know Instruments form Apple’s developer tools. Instruments is mainly a tool to benchmark your own apps, find slow parts and fix memory leaks…

…I let this run for two hours and as you can see in the rightmost column, the Facebook app is waking up at regular intervals, does something for almost exactly 10 seconds and sleeps again. The whole day long.

This explains why this app is in the first place in the CPU time listing.
Theoretically the app could use your location when awake and send it to Facebook, but I found no evidence for that.

In short, this is one of the few cases where opening multitasking (double-tapping the home button) and removing an app from the list actually does close it and helps CPU/battery usage.