Yesterday, I returned a 3rd party battery grip (amazon) because in one 7-day period, the battery charge dropped from 100% to 24%. Less than 20 images were shot, and the camera turned off at all other times. And I wasn't walking around with it.
This happened twice to me. Same numbers on the battery charge. I tried it once with the Nikon battery in the body (grip attached). And then once again with the battery in the grip. The EN EL-15 battery.
That's why I took the D7000 body and EN EL battery to Nikon a week ago. To ascertain if the fault was in grip (which spooked me anyway by being a non-Nikon accessory) or the fault of camera electronics and/or the battery itself.
No more Chinese camera accessories for me. Aside from this, I wonder if I am setting menus too often. Could it be "operator error" that causes battery drain.