So here at Zimbra we also have different expereince regarding battery life from user to user. For example, my iPhone actually holds battery really well, even though I have push email turned on and I hear beep of incoming messages all day long. Some other users can only last to noon even after they turned off push altogether. I'm not sure if it's related to battery age and remaining capacity. If it's age alone then it doesn't explain why my iPhone is better since I waited in line a year ago when it first came out, and have since charged the device everyday.