7d Battery Grip Error code

Bought a 7d a couple of weeks ago & also a generic Battery Grip from eBay. Used the combination for a couple of days & all was fine. The first time I came to shoot a fast burst the camera froze & showed the error code "80" I took the batteries out & re-inserted them. This cured it for a couple of shots then the same thing happened again showing the same error code. I removed the grip & re-fitted the original battery cover complete with the single battery. All works perfectly. I tried the grip again after checking all the contacts. After a few shots the same code came back up & the camera froze. Once again, when removed & original battery replaced, all is fine.
I have 4 batteries, 1 genuine Canon & 3 generic ones. All are recognised by the camera.

Any ideas??

https://photography-on-the.net …/showthread.php​?t=1242244

I know it doesn't deal with the battery grip, but a canon response is usually pretty accurate. Granted, a no name grip can easily cause problems as well.

Rashkh wrote in post #15760646
https://photography-on-the.net …/showthread.php​?t=1242244

I know it doesn't deal with the battery grip, but a canon response is usually pretty accurate. Granted, a no name grip can easily cause problems as well.

Many thanks for that. I will have an in-depth look. I have just refitted the grip with 2 fully charged batteries & have tried 2 high speed bursts. All seems fine???
When the errors occurred it was cold outside. (One day snow, the other just cold!) Both the batteries on both occasions though were fully charged.

Could it have been the cold?