It's no secret that we generally enjoy Braven's pushes into the portable Bluetooth speaker arena. The company is again aiming to take your dollars away from the likes of the Jawbone Jamboxes, offering up two new units for CES. The 850 is it's largest speaker yet, being roughly the same size as Big Jambox -- and priced much the same at $300. As you'd expect, the 850 is clad in aluminum, and has a USB port for charging external devices. That's not all, however, as Braven claims this is the worlds first batte