The Canon BG-E11 Battery Grip is
an optional battery grip with improved ergonomics designed specifically
for the Canon EOS 5D Mark III, 5DS, and 5DS R. It allows users to load a
choice of one or two LP-E6 battery packs. With two packs, the
already-impressive battery life is doubled, compared to using a single
LP-E6 pack in-camera. This is especially useful when taking advantage of
the camera's movie mode or Live View mode - operating modes that use
more power. In addition, with the included battery magazine, you can
also run the camera off six AA batteries.
The BG-E11 also
provides full vertical shooting controls, which can be independently
turned on or off as the photographer needs to enhance camera handling,
especially for shooting vertical pictures. It has a large number of
operating controls as well: shutter button, Main Dial, multi-controller,
AF point selection button, AE lock/FE lock button, AF start button, and
multi-function button.