[FuzzyDangler]

I had charged my GS3 earlier in the day. It finished charging right before I went to bed. I decided not to plug it in last night and awoke to a completely drained S3. I have battery saver on, closed all backgrounding apps and cleared up my ram before going to bed. I'm not sure what the issue is. If anyone else has had this issue or anything similar, please let me know.

[Shawn Magm]

You probably had the dreaded battery plummet. Lots of threads on this. There have been many suggestions. I would recommend restarting the phone before going to sleep. It's a minor pain, but it might work.

[Voliam]

Look in settings- battery and see if some app is causing the problem. Ironically, the last two days my battery was drained after about 15 hrs of minimal use. Was shocked to get the low battery alarm both times. I found, for reasons yet to be determined, that Dolphin Browser was eating up data in the background, as well as draining the battery! I have never had this issue, and always exit out of the browser when I'm done. I'm currently monitoring this and searching for a cause/ solution.

[Uncle Reemus]

Download GSAM and see what it tells you is eating your battery, it also tells you your battery temp which I have found a high temp leads to my phone draining very quickly.
Also Juice Defender and Advanced Mobile Care help alot.

[meyerweb]

Hi temp is a symptom of what's eating your battery, not a cause.

[mdcraig]

If you are rooted, I highly recommend the app Greenify. It will tell you what apps are running in the background at all times, and you can hibernated them so they don't until you next use the app. I've seen a 30%or so increase in battery life since using it.