I've been travelling a lot the last 3 weeks and I found that signal strength had the biggest impact on battery life. I play with the phone often enough to call it "moderate" use. When I was on the 44th floor of a building in chicago with 3G going in and out and no signal in the elevators I was barely getting 12 hours before it was in the red. However, when I'm at home or my normal office where I have a constant signal (and access to consistent wi-fi) I go the full day (8am until 11pm) and the phone is usually around 50%. This is standard battery btw. I bought the extended (backordered, hopefully it will ship soon) just to take any concern about battery life on travels out of the equation.