I'll add that your battery should have a strap around it too to physically secure it to the fuselage. Some of the harder maneuvers we do can produce 10 G's, so your 6 ounce battery will pull on the velcro with 60 ounces of force. Velcro to keep it from sliding and a strap to keep it on the velcro results in a battery that will never move until you want it to.