When the camera is turned on, the MB battery icon (not the standard icon, but another one) on the top LCD flashes until the first half-press of the shutter release - it then goes steady. This effect is odd, and I have found no explanation for it, including posting on this forum, with no responses. However, this characteristic does not seem to affect performance of the camera.
It comes with two trays - one takes 6 AA cells and one takes a standard Nikon battery. With one battery in the camera, the double-pack in the grip, a spare Nikon in your pocket and 6xAA cells, you have loads of capacity.
The reason that the battery meter on the camera is flashing is because the camera cannot get any information from the battery you have placed into the camera. The camera knows a battery is there since it is delivering power but as it is missing the correct circuitry the camera is confused - not a good situation
The trays come with the MB-D11.
Iain Morrison LRPS CPAGB