Exclusive to the EOS Digital 400D, the Canon BG-E3 Battery Grip functions as both a high-capacity battery pack and a vertical grip. The grip accepts up to two NB-2LH battery packs; approximately doubling the camera's shooting capacity, and it can also be used with six AA batteries in the supplied battery magazine.

This grip provides additional controls for easier vertical shooting: shutter release, AE lock/FE lock, Index/Reduce button, main dial, and AF-Frame-Select button, Aperture/Exposure Compensation button.