We thought that we already knew just how glorious that Canon’s $US2,699 EOS 5D Mark II would be, but the camera has one trick up its sleeve that’s more practical than another megapixel boost, or maybe even its ability to capture 1080p HD video. Seriously. The camera can keep track of up to six batteries in its internal database, managing which of them still have juice.
The technology isn't extremely complicated, just clever. Each LP-E6 battery pack contains a microchip with an 8-character serial number. In the camera menu, the battery/chip can be registered to be tracked by the camera.
From there, the Mark II tracks the battery's charge by single percentages along with how many shots the battery has already captured. Put a photographer in a dark room and multiply his battery load by six, and it becomes obvious why many pros and consumers alike will take advantage of this feature. [Canon via Engadget]