I would worry about there being enough threads in those joining nuts. There are specific nuts used in Unistrut for joining threaded rod that provide much more threads to be used.
Otherwise, that's pretty cool!
It is not visible on the picture, but the stud has a little weld to the bolt. They won't come off.
This is a stationary battery, and the studs are 10 mm away from the cells, so i have no fear for damage to the cells