Yeah I'm going to let it completely die on this charge because that's a little fishy to me. It's an iPhone 4 and I've had it since release and I've never had battery life anywhere near that. I was texting and using Facebook and Twitter while listening to music. No way it would still be at 100% after that long.
Right now it's at 90% with 4 hours 38 minutes usage and almost 14 hours standby.