My Zeikos ZE-NBG5000 arrived in the mail on March 5th. After charging up the 2nd Nikon battery that was also ordered with the unit I was able to test it out on the 6th with the following result;
1. using battery 1 of 2 and the unit works
2. using battery 2 of 2 and the unit works
3. when both Nikon EN-EL9a batteries are used in the unit "at the same time" I receive a dead battery symbol in the view finder and this message on the LCD screen;
"This battery can not be used. Choose battery designated for use in this camera."
I wanted a dual battery system so that I could shoot timelaps day & night exposures plus all day events. My supplier will take it back but I must have the original box that I came in. Here in the wilds of Williams Lake, BC, Canada, we recycle everything... my wife recycled the cardboard box while I was out testing the new grip yesterday. I can't win for loosing on this product, eh...HB