Well, the Mugen battery doubles your run time from the stock battery. So 7 hrs of runtime on a stock battery would translate to 14 hrs on the Mugen. I used the thing while I was out in Las Vegas at CES. Watched movies and listened to music almost the entire way out, plus time before the flight, and after, and hardly touched more than a quarter of the battery. Of course, after CES, I found that I didn't use it anymore for the above reasons.

That's why I sold mine off. Now if Mugen starts selling their product with a metal cover, I may consider one again. I say *may*, because the times when I really need the extra battery life, such as on previously mentioned long rides (plane, car, etc), can easily be supplemented by my Tekkeon battery pack. Once I'm no longer sitting still and I'm on the move, the battery pack isn't needed anymore.