About a year back my battery cracked my canopy while doing extreme stunts. Don't know if I fail to secure battery. Then flying that way for well over a year.

Two days ago my battery was ejected from the plane while doing the same thing as above, I remember strapping the battery even slightly repositioning it and I'm sure I pulled the strapp velcro tight. Luckily my vyper had a receiver battery so I still had control of the aircraft and landed safely even though CG was way off. Canopy was found on the ground on the pavement in 3 pieces. Battery was upwind from that about 150 ft and landed on mowed grass, fell from at least 130 ft or more. Surprisingly just slightly puffier than before rejection. Still works and have flown with that battery after ejection. I keep my batteries outside so I don't have to worry too much about fire.