QUOTE(Moogle Stiltzkin @ Sep 17 2012, 10:07 PM)
which rom and version you using ?
how often is your device syncing ? I recommend setting your apps that do sync, to do it only once every 24 hours .... don't sync too often.
when phone not in use, disable wifi ....
gps and gestures disable .....
It's a bit mahfan for me to on off wifi manually. So instead i use GreenPower that automatically on/off it depending on how i use the phone. For example when the screen times out, it will turn off wifi. When i turn on phone screen, it will re-enable wifi .... see ... this is better than manually on/off yourself :} and saves your power too smartly...
stock ICS with touchwiz
need my emails and some apps to be synced every now and then (all on wifi, no data plan)
the prob is, my previous galaxy w can last 2 days with the same usage pattern
of course you have to take into consideration the bigger screen, but s3 comes with 2,100mah batt vs the w which only has a mere 1,500 mah batt