This sled is designed for the manufacturer recommended 1s 400 mAh battery only. To secure the battery, slip the battery into the pocket on the back of the sled with the wire end toward the top. Place the battery retaining clip in place with the wire passing out the top, and secure with two 4-40 screws from the front of the sled. Check to make sure the wire has not been accidentally pinched. The wire can be routed two ways, either through the notch on top and down the channel on the front of the sled, or through the nut capture opening (this method may require an extension to reach the tracker terminals). NOTE: Using the shockcord sleeve will require the use of an extension cable for battery hookup due to the clearance issues with the stock connector. You can simply solder a short wire lead to the manufacturer provided connector.