[azdeltawye]

So, as a follow up, I'll probably buy a box of M8 x 1.25 SS socket set screw bolts, 30mm length. Box of 100 is $30:
...

No need to spend the extra money on socket head set screws. Just get standard stainless steel studs. Install them in the battery terminals by using two nuts tightened against each other. Then once installed in the battery, remove the jam nut and you're done.

The same way you would install a stud in an engine block or motorcycle case...