Ok, so this morning I was having battery issues as mentioned (10% in 2 hours) even though I wasn't running the TweetDeck widget anymore which I thought was odd. But I DID have wifi on last night (after not using it all day since my last reboot). I uninstalled TweetDeck this morning, but I ALSO rebooted the phone (not just restart, but actual reboot). After that the battery usage went back to normal again (5% drain in about 5 hours). I just assumed it was from the TweetDeck uninstall, but maybe it was the reboot. I turned wifi on again when I got home today and looking at the battery graph it looks like it's declining really quickly again.
So I think you might be on to something. It seems that the wifi isn't turning off correctly or something. Or could it be some kind of combination of having wifi on, the wifi sleep policy, and the fact that I'm running JuiceDefender which is only turning data on for 1 minute every 15 minutes? I always thought wifi would use less power, especially if it's sleeping. But it seems there's some kind of bug that prevents the phone from sleeping if the wifi is on. Is this an Android bug or a Samsung bug? Do you have to an actual recovery mode reboot or just power off and then on again?
These are my findings from the month that I have had the phone. When my phone drained 70% overnight one night, I pretty much had the same reaction as you - what did I install that made my battery drain? I started to uninstall pretty much everything and did a reboot and it seemed like my phone was fine when I was in Spare Parts. My phone was sleeping and I just chalked it up to a bad app that I installed. Throughout the next day, however, I noticed that the problem returned. I was again frustrated, but more so this time because I didn't install anything new. Again, in a fit of rage, I uninstalled pretty much everything to the point where it was stock. At this point, I thought what the hell? Why not just reformat (factory setting) the phone? I did this and when it came back, everything was good again. I made it a point to not install any apps for a few days and keep the phone as stock as possible. The night I went to bed, I left the phone off the charger and it drained again. At this point, I thought there had to be a defect with the phone. I was almost to the point where I was going to get a replacement, but out of sheer randomness, I decided to turn off WiFi and leave my phone using mobile data indefinitely. I went to bed the next night and lo behold, I wake up with only 1% drained. I tried this again the next night and the same thing, only a few % drained. Running % was down and Android System wasn't holding a wakelock. I began to install the apps back onto my phone and strictly only used mobile data from then on. My phone hasn't had an issue since. It's been a few weeks now.
Few things:
- To answer your question, it has nothing to do with the sleep policy or any apps you download. It's just something faulty with the sleep policy. It seems that no matter what policy you change it to, WiFi will not let the phone sleep. If you set the policy to "never", you'll notice that the Running % and Android System will be maxed out. The bug is that even when it's set to "When screen is off", it still doesn't really do that.
- When I say reboot, I mean just a simple restart (turn the phone off and turn it back on).
- When WiFi is turned on, it seems like it doesn't "bug" until a few hours down. For example, what I noticed is (at 100% battery) when I turned WiFi on, it would sleep correctly and everything for a few hours. But once I got down to like 60%-40% (3-4 hours later) it would then all of a sudden decide to not sleep and hold a wakelock. This means that it isn't instant. It takes time to "bug".
- Once it is "bugged" nothing will "unbug" it until you restart. That's why, in my last post, I told you to restart the phone before you discredit WiFi as the culprit. You having WiFi off later on in the day did nothing as it was already "bugged".
- My suggestion is to simply leave WiFi off and use mobile data. I'd rather have the piece of mind knowing that my battery isn't draining then have an extra 2-3x the speed. Nothing I do on my phone is that speed intensive anyways. But then again, the reason I can do this is because I have a 6GB data plan. For those that have a limited data plan or would still prefer to use WiFi, just reboot every so often when you noticed your phone isn't sleeping. It really is a hassle though.
Tell me if you have any new findings. I wouldn't mind using WiFi again, but for me right now, it's never touched anymore and I get by fine. Hope this helps!