Just got a Nikon D750 with an MB-D16 grip and very excited to be back to full frame after DX for some years. I specifically like using the grips with the AA battery packs because of the convenience of the plethora of NiMH AA batteries I have around; however, first time using I would get ERR message on the LCD after about 20 shots, the mirror would open and lock in that position, a quick look online and I found that setting the camera to Mup on the dial would get the shutter back down and out of ERR mode, but a few shots later it was back to ERR. I thought I got a bum camera that I'd need to send back to Nikon, but I decided to switch the battery order back to Camera > Grip (Custom Settings Menu > d Shooting/display > d12 Battery order > Use camera battery first) and guess what, no ERR or lockup issues; whereas previously I was getting ERR about every 3-5 shots. I decided maybe it was the battery's since they are going on a couple years, so I ordered some brand new Powerex 2600mAh batteries and after a run through the La Crosse charger put those in the grip, checked the battery level in camera (Setup Menu > Battery Info) and it showed full charge so I thought great, that should do it. I switched the batter order back to Grip > Camera (Custom Settings Menu > d Shooting/display > d12 Battery order > Use MB-D16 batteries first), set the camera up to do a video and within 10 minutes the battery level was showing red and one bar... what on earth So I switched back to camera first and finished about 25 more minutes of video without issue, then set the battery order back to grip first and guess what, charge shows full again? Yes, Custom Setting d11 is setup for MB-D16 battery type of Ni-MH. Further research online seems to indicate Nikon has had some issues with their grips and NiMH batteries and not being able to assess the voltage correctly. Do I need to send my grip to Nikon or is this what I can expect when using the grip with NiMH batteries, sure I can use the other battery tray for the EN-EL15 battery, but that's not why I bought the grip. Any suggestions would be appreciated, thank you.
So I switched back to camera first and finished about 25 more minutes of video without issue, then set the battery order back to grip first and guess what, charge shows full again? Yes, Custom Setting d11 is setup for MB-D16 battery type of Ni-MH. Further research online seems to indicate Nikon has had some issues with their grips and NiMH batteries and not being able to assess the voltage correctly. Do I need to send my grip to Nikon or is this what I can expect when using the grip with NiMH batteries, sure I can use the other battery tray for the EN-EL15 battery, but that's not why I bought the grip. Any suggestions would be appreciated, thank you.