The post is a standard round post (like a car battery) on top of a 2v cell. The cable has a round lead molded end that is slipped over the post and sweated on with an acetylene torch.
Repairs on youtube show a hole saw used to remove the outside ring, and a new cable is sweated back on the way the original was.
The videos all show the person removing the vent caps from the adjacent cells, blowing the battery top with compressed air, then sticking the lit torch into each cell briefly to make sure they don't detonate when sweating on the repair.
The use of a torch also transfers so much heat to the repaired cell that wet rags are used to cool the cell tops.
I cringe when I see these guys shoving a lit torch into a cell full of H2SO4 but I guess it must work at least most of the time, as they are still alive and can still see.
https://www.youtube.com/watch?v=KEaUz63seb4I think I just got an idea. Instead of sweating on a repair, I could get a car battery repair cable with the bolted clamp and simply clamp a long cable on the same way you would attach a car ground or starter cable.