Murman made a coroplast canopy for SEFF combat.
Wam74 says: "I don't run a canopy and wasn't totally happy with just velcro on the battery. So I made a holder. Straightened a paperclip, bent it into a hard C the width of the battery and pushed it up through the foam from the bottom side. Cut the wires 1/4" above the top of the battery (topside), bent them into opposing hooks and stretched a 1" O-ring between the hooks, securing the battery. I still leave the velcro in place to keep it from sliding around on my less than skillful landings."
Murman did this: "I modded my SF so that the canopy would break away in a crash. I used velcro to hold the battery to the canopy and then tiny rare earth magnets to hold the canopy to the deck. Since the battery is the heaviest part of the SF, my thinking was that if it broke free in a crash then the SF itself wouldn't get damaged. It actually worked very well and I'm sure it saved having to make some repairs."
The battery is nicely protected as you can see.