Originally Posted by inFECT

I get 3-4 days on JB2 with avg. usage. Means: 30-60 min phone calls, 30-60mins wifi/3G and few SMS. Autosync emails are always on.

Overall the Donut Firmware is the best in terms of battery life so far.
(As long as i dont get hit by the sleep bug, which i learned to prevent anyways)

Friend of mine is on II5 and use the phone a lot more. Like 2-3 hrs a day phone calls. Bluetooth always on with Headset, more browsing.. etc.
Dont know why, but he manages always to get at least 48hrs out of it.

That said: As long as the phone works properly and no battery app drainer are running, the lifetime is great. Compared to my old Hero and the new Nexus, the Galaxy beats the crap out of them.