I got the extended battery for my S4 before I even got the phone. I assumed that, with all that horsepower under the hood, I'd need the extra juice. Wrong. At the end of the day with the typical amount of useage, I've still got 20%-30% power left. I'm pleased as hell. The only problem I'm having is setting up my email account. I got gmail working instantly but my personal email ain't happening. On the phone with tech support as we speak.