Fri 06-Jul-12 02:00 AM | edited Fri 06-Jul-12 02:03 AM by DavidN4
I have a D5100 and the Mieke/Neweer battery grip. I've had it a pretty long time now with 2 cheap generic non-Nikon batteries. I get just as much shooting time out of the generics as the real Nikons (I have 2 of them also). I've shot a couple of all day events with flash with each type of battery - no difference. I usually just leave the generics in, and shoot them more.
When you put in the batteries (if there is no batter in at first), load in one Nikon battery and let the green light on the back of the camera light up. Then add in one of your generics. Pull out the Nikon battery and load in the other generic battery. Then you are good to go.
With 4 batteries, I can shoot all weekend without ever looking to see if I need power, and I am not tied to trying to find a place to recharge. Instead of $40+ per battery, I can play $8 per battery.