There are several reasons why you should get a good battery grip for your DSLR camera. One is that you can insert one or two extra batteries inside so you won't run out of power when you need it the most. Another is that most of them have a shutter button built in, allowing you to take pictures easily when your camera is at an angle. Finally, they just look cool. The best thing about having a battery grip is probably that it makes you look like a more professional shooter. Units from the manufacturer are quite expensive, but you can find some cheap battery grips online.