I bought the original iPhone a month after it came out last year, just got my 3G iPhone last thursday, and the battery life is terrible....
I updated to 2.0 on my old iPhone the morning it came out, and noticed a little lag in operation (but to be expected, no complaints), and no difference in battery life even after playing games, etc. the first couple days.
I am on 2.0 5A347 on my 3G, and currently (as I type) my usage since last full charge is as follows:
3 hours 3 minutes, Standby: 9 hours, 17 min, and I'm sitting at 25% battery, just the last sliver of green before the red comes up.
I habitually charge mine every night before I go to bed, and I just can't imagine my year old iPhone having better battery life?!
I took a look at apple's solution (don't get me wrong I love them, I've owned 2 iPods, 2 iPhones, and am typing this on my 17" MacBook Pro, blah blah...). It seems ridiculous to have a phone to have these features but you /shouldn't/ use them to conserve battery life (the usage is all within reason, I'm not complaining that I can't watch every episode of Entourage on a charge). It says to turn 3G, location services, bluetooth, wifi, push email off?!?! Turning these things back on takes as much time as it does to open my laptop, and also kind of defeats the purpose of having an iPhone if you ask me. The kicker was also to put it in Airplane mode if you have limited service, then you have a $300 $130/per month iPod touch...
And the master reset function (home and lock buttons held down) didn't do anything, as I've hit that every time my ringtone and text tones stop working, which I've notice happen quite frequently, as well as the phone 'disconnecting' from the charger after being on it for 2 minutes. Real nice waking up to a dead phone, I'm just glad it was Saturday... I proceeded to plug it in again, it would charge for 2 minutes then disconnect again. Did this about 5 times, then just magically stopped.....
So I don't know what's up. I'll try the master reset, again, and turn all of the features that me it an iPhone off, and try that tomorrow, if it's not any better, I would hope they would take it back.
Who else has had the same issues, and if you've found a way around them, let me know!
This will be duplicated in the iPhone 3G battery life thread as well.
http://www.mac-forums.com/forums/showthread.php?t=115609&page=2