I was able to make it 2.5 days on light use a couple of days ago. I actually wound up killing the battery on a long phone call though. Interesting there was no audible warning that the battery was that low, the phone just killed the call and shut down...
Anyway, i charged it all night, then used the phone very lightly the next day. Checked facebook a couple of times, and wrote a few text messages. It was at about 80% when I went to bed. Woke up this morning and it was at like 20%. I have no idea how it could have gone all day barely using 20% of the battery, then be on standby all night and use 60%.
There is likely a problem with the battery reporting?