Aputure Battery Grip 5DMIIL - Handbuch (Seite 15)

NOTE
Be sure to attach the battery grip to the camera before inserting the batteries. The batteries.
The results of the battery check may not be displayed properly If you attach the battery grip
to the camera with the batteries already inside.
Before removing the battery grip from the camera,bu sure to turn the camera’s power switch
to <OFF>,and take out the batteries.After removeing the batteries.attach the protective cover
to the electrical sontacts.