Battery life is one of those things that for some reason after all this time of having such high powered smartphones in the industry, just shocks people. I mean really shocks. Consumers get a smartphone, use it all day and say to themselves "Wow. This phone sucks. I can't get a freaking day out of it!" not even realizing it's not their phone, it's just the fact that battery technology hasn't caught up with us yet. So nomatter what phone you get, it's gonna have shitty battery life when you use it 10x more than your old flippy
/rant
Sorry. I was in the moment and the moment said rant. But really, the battery in this phone is just okay. The great part is how 2.2 and this phone manages power. I have mine on "night time saver", so during the day my phone is normal, but when it's whatever time "night" is, it goes into a lower powered state. Not syncing as much, gathering as much data, using as much screen. Stuff like that. It's pretty cool. So battery? The capacity is just okay. But the way this phone manages it makes it last a surprisingly longer time than my old eris. Woke up this morning with a full charge, used it for mostly web browsing (and battery hungry flash videos) and by about 3pm had a 50% charge. I use my phone to ignore my annoying girlfriend, so i use it alot. Seriously, i could write a testimonial about how little i've actually listened to her since i've gotten the phone. ALOT.
I bought a spare battery at verizon today so i'll always have a backup, but if you don't have a chatty girlfriend, you should be okay