5D3 & Battery Grip Issues

I just found out a weird thing with my 5D3, Canon battery grip and the Manfrotto plate. Would someone let me know if they've had this issue before. I've had this combo for 5 months and this just started. When I have my grip attached to the camera and the plate screwed to the bottom of the grip, when I turn the camera on, it says "can not communicate with second battery." Then I have the option to hit OK or Cancel. I hit OK and then my battery shows completely dead (this is right after pulling off the charge). I take the grip off and the battery shows full. It seems like the screw from the plate that goes into the battery grip is shorting it out. WEIRD!!! Going to take it into the camera shop tomorrow. I hope its just the grip which was very expensive.

It could well be that the bolt(screw) is too long and causing the battery to be pushed upwards enough to lose contact. Try putting a washer of any size big enough for the bolt to go through between the plate and the grip. If it solves the problem, the bolt is too long. Either find a replacement bolt a little bit shorter, or, grind that one down by 1/4" or so, taking care not to end up with damaged threads.

Following on . . . does the phenomenon manifest immediately the plate is screwed on . . . or only when the grip, body and (heavy) lens are mounted on the tripod?

If the former, then Bratkinson probably has the right of it; I can't think of any other way the plate would affect power delivery.

If the latter, then it may be flexion between body and grip breaking the circuit as the weight of a lens applies torsion. This was an issue with the 20D and original BG-E2 grip - but I've never heard of it affecting the 5D III and its grip.

Going off of this, did you just upgrade the firmware on the camera? I upgraded last week and went to shoot a wedding, turned on the grip and the camera just started shooting on burst and wouldnt stop! Pulled the batteries, card, you name it and it wont stop! I couldnt use the freaking grip. Vello grip, even genuine canon batteries, aftermarket, etc they all did it. WEIRD!

Thanks for the input. I haven't actually had the camera on while screwing or unscrewing the plate. I will try that but it does make sense the bolt could be causing the issue. It's just weird that after 5 months it decides to start doing it. I haven't upgraded any firmware yet and honestly I don't know how to do that. I'll let you guys know what the repair shop says today.