Here are some pics of the battery side. There is a locator on the inside both front and back. The fit is good on the locators and the tape slots are right at the edge of the battery. In the picture without the battery you can see some of the almost 100 grams of weight added to make weight. The piece used is from the photon balance weight set, it is cut down to length and notched for the servo to fit in where I have it.