Take a look at these new battery holders from Secraft. These anodized aluminum trays mount very easily to a flat surface, and allow for simple battery installation and removal. The rubber strap provide added grip for a secure hold. Available in two sizes, and two colors.
https://www.espritmodel.com/battery-tray-holder-aluminum-anti-slip-m-115x50mm-39g.aspx
https://www.espritmodel.com/battery-tray-holder-aluminum-anti-slip-s-83x47mm-23g.aspx
