So I've had my Thunderbolt since Friday and I've went through the process of calibrating the battery. Yesterday I got a complete day out of it...took it off the charger at around 7:15AM and it lasted till 10:30PM and wasn't dead. This was with moderate to heavy usage throughout the day, syncing 3 emails, listening to music, etc. I don't have juicyfruity defender or any task killers installed either, just letting Android do it's thang. Now I'm not on 4G so that may be why I'm getting a full days charge with the stock battery, but so far I'm not disappointed with the battery life. Still really enjoying this Bolt, was a worthy upgrade from my beloved OG!