The bolt that fastens the battery holder down to the chassis is stripped. It's stripped so bad it's an oval hole now.

Any recommendations on a way to fix this? Don't want the battery loose in the engine bay if it doesn't have to be.

Tried to helicoil it and the hole is already too big for the tap.

Would a threaded rivet insert do the trick?

 

JBweld a nut on top of the hole?

 

I went ahead and used a threaded rivet fastener. Tool was $40.

Just had to drill open that hole a little larger, insert the rivet, and now I have a thread that's good as new.

I did use a stainless rivet to hopefully avoid future rust.