I have a big fat 3500 mah battery. I also own a Defender. I put my EVO in the plastic Defender case WITHOUT the battery back on. I did not try to close the plastic case (it won't close), I just carefully stretched the rubber exterior over my ghetto rig and voila, IT FITS! The answer is: 1) Leave the battery back off. 2) Don't try to clip the plastic case closed. 3) Carefully stretch the rubber exterior over. P.S., Can't take a pic because my camera is on the phone inside the case. Basically looks like a Defender only a little fatter.