70d battery grip question

[BraCas]

I just got a VELLO battery grip for the my new 70d. I was reading the directions to it and trying to figure it out. I was wondering how to tell which battery is being drain first. After writing VELLO, their response was it can be done in the custom controls of the camera.I can not find it in the book. I look at the battery info and they seem to drain equally when I use it. Is there a button or page in the menu that I am missing?? can anybody help set the camera up so I drain one battery then the other??thanks

 

[vimwiz]

They are speaking rubbish - The batteries are wired in series as far as I know, and the camera cant read any intelligence from them (it doesnt have its own charge circuit / battery controller, it just uses the columb counter in the body). So no, no way to tell IMHO.

 

[fokker]

I highly doubt the batteries would be series wired as that would double the input voltage.