Pixel BG-E11 draining battery

I have no eyefi card or any accessories.

With 3 different sets of battery and the camera off if I insert a new set of charged battery and the Pixel BG-E11 grip is discharging the battery. By a few hours its down to 90% on one battery.

I have even removed the lens, charge up the battery and by the next morning it down to 80% charge on one battery and 90% on the other.

I have also used a different 3rd party grip on my 5D II with no issues that I still have.

I also used 3rd party grips on my previous camera with no issues like the 7D, 60D, and Nikon D7000.

The weird thing is that it discharges one battery faster than the other.

I contacted pixel support and they said to send back the grip.

Has anybody experienced this?

I sent another email asking what going to happen do they have new grips that dont have this issue or will the ebay seller refund my purchase.

This is too bad as I love the feel and construction of the grip.