It depends on what AA cells you use. I am using a set of brand new NiMH cells to form the battery. Each cell is rated 1.2V 2000mAh. So the battery is 6x1.2V = 7.2V 2000mAh, which has higher voltage and capacity than the Nikon EN-EL15, which is rated at 7.0V 1900mAh.

My shooting last longer, typically well over 1000 shots. I am now happier to use the built-in flash and lots of in-camera editing.

If you mix and match old and new cells, which make up the battery in the Meike grip, your shooting experience may be shortened.

The number of time you could charge Lithium Ion battery (Li-On) is around 1000 times, in theory, you should charge it when it is nearly empty, but not exhausting it. There are many theories, I just stick to this one.

So It is cheaper to use AA cells to make up of your battery, as an EN-EL15 battery costs £77 in the UK.

As a result, I use AA cells mainly to shoot happily. The only problem is there is only two indication of power left in the grip. One is full and then half full.

When it is half full, I can take about few hundred more shots. It then switch to the battery inside D7000 body, without warning. It would be great if there is a warning beep or something to notify the user.

Is there a warning beep for battery swap-over? Is it in the manual? I have switched of the beeping sound for key press. I will try it with it switch on next time I use the camera.