Hya, first post on here so apologies if this has been posted before. I have a Sony Experia SP so how effective this if on other phones, i'm not sure but i imagine the problems is with android/facebook in general. My Experia when i bought it estimated 4 days battery however after a weeks use this went down to 2. I'm a light user and with the massive battery in this i expected better battery life. I did some investigating online and eventually found out my phone wasn't sleeping properly when the screen was off, in battery info my phone was awake a lot when it was supposed to be asleep. I downloaded the Wakelock Detector and found which app was still running in the background, damn Facebook... even with notifications off as i only check it manually. Facebook was even waking the phone with airport mode on! It seems the facebook basically overrides everything in the phone, stamina mode, networks off, sync off, airplane mode, how they get away with this i don't know Anyway to cut a long story short, i disabled Facebook totally and my battery life has literally doubled from 2 days to at least 4 days under light use (airport mode during the night). this for a smartphone is incredible, and to think Facebook was constantly draining battery and making a massive difference is ridiculous. Imagine everyone who uses Facebook on there phone (pretty much everyone) and its basically halving their battery life! Rooted phones may be able to hibernate the app, my phone wasn't rooted so i disabled it completely and will check facebook from now on in the mobile site, which isn't bad anyway. Hope this helps someone who is wondering why the hell their battery doesn't last very long.