Hi guys, I've recently purchased a CYMA m16a1 which has a pretty much entirely hollow stock for housing the battery, meaning that it tends to rattle about when moving. I've seen people suggest lining the inside of the stock with velcro, or to cover the battery in bubble wrap, but I'm not convinced that's entirely safe (would it not increase the chance of the battery overheating?). Just wondering if anyone has had this problem before and can give some advice. Thanks!