That said, my last phone was a Thunderbolt with an extended battery, so it's safe to say that I won't mind a bit of thickness.

ENGADGET: Ask Engadget: best case for the Samsung Galaxy S III? Mobile

To power this beast, Xiaomi's throwing in a 2, 000mAh cell, but you can also purchase a 3, 000mAh version if you don't mind the extra 2mm thickness on the phone.

ENGADGET: Xiaomi Phone 2 now official: 4.3-inch 720p IPS, quad core and Jelly Bean for just $310

While it isn't built into the hardware, it doesn't seem to add much to the weight or the thickness of the case and thus the device itself.

ENGADGET: Nokia Lumia 820 review: a less expensive option for the Windows Phone crowd