Battery life on Android has been a bit of a sore spot for many users, mostly because it's simply not good enough. Most devices can make it a day on moderate use, and a few can even do so comfortably, very few phones can hit two days without some time on the charger. The Android "L" release is making several improvements to power efficiency via Project Volta, but there are also ways to improve 3rd-party apps, and that's where the new Job Scheduler comes in.
A few days ago, we reported that the Facebook app had been updated, and now included “less suck”; turns out we may have been wrong (that pun will make sense in a minute). Flipz, the developer behind the awesome Fresh ROM’s, has done his homework and found that the updated Facebook App has a wake lock bug that drains the battery fairly significantly.
As mentioned, the problem arises from the wake lock.