Yes, I had secured the battery with a battery strap within a battery box. I am next going make a battery tie down strap using a ratcheting strap (constructed by cutting down a longer tie down strap from home depot) so I can feel more secure about the strap remaining tight and to make it easy to check and retighten.
I found on a fiberglass supply sight that the strength of the tape is about 100 lbs / inch in the direction of the fibers, so I suspect that that would be plenty strong enough for a strip running inside the cabin. I am also considering adding a strip in the galley (belt and suspenders).
If the problem recurs I will consider the lithium route.