Question about Canon Bg-E21

If you only have one battery in it, I would mount it in the other compartment. If you have mounted a silicone cover on the camera, you have to tighten the set screw of the battery grip really tight. But without tools!

The battery grip itself still has an on/off switch, is this on? Fully screwed on? Sometimes the batteries are not fully engaged in the compartment. If everything is correct and nothing works, you cannot rule out a defect. The best thing to do is to contact our customer service at digitec@digitec.ch :)