Unfortunately I can, like so many before me, do not speak positively about the battery grip. First, the plastic is not particularly high nor processing. Especially the battery cover is completely rickety. Nevertheless, as I thought, it will serve its purpose. BUT, despite two NIKON battery, my camera was unfortunately an error in the hardware. The battery can not be used ...? Strangely, there are still both Nikon batteries and they are also, in each case individually, accepted by the camera. Once I recognized the handle, the error message on the display and nothing works. Too bad, the handle goes just back I thought to myself. To make matters worse my camera now seems to have a software crash or the like. Now, the error message always appears. No battery is more accepted and the camera must have the Service. I do not go on, because I'm no longer in the menu to perform a reset. After some research on this issue, I came across similar problems. Apparently it has something to do with luck, if the camera accepts the handle or not. So my poor rating. Unfortunately, there is for the battery grip for D5100 no real choice and so I now renounce this gimmick and simply switch the battery when one is all! I've always just a charger.