Samsung excess battery drain
Twice this month my s3 has run the battery flat in 5 hours. After charging and restarting it went back to running it down at 3% per hour. Prior to this it used just under 2% per hour. I have also seen the phone wake up for no reason, several times, during the night. It has also been very slow and unresponsive a few times, fixed by restarting.
Any idea how I can find out what is causing any or all of these things?