Battery age issues
It's a fault, 100% it's a fault. My D800 battery (same battery) within 1,000 shots was moved to 1/4 on the battery age meter. It was getting ALOT LESS than the rated shots per charge. I complained, Nikon sent another one. Don't accept it. The battery age should be at 0 for a long time. My D700 was still at 0/4 after a year.
Thanks Primeshooter for your info!