For batteries we got cables with the lead loop terminal on the end. Used a drill to remove old cable that left a post on the battery. Kinda like a thick hole saw with a spring loaded center. Sit the cable over the post. Wrapped wet rag around it. Melt the post and work the edge of the terminal into the puddle. Then add lead to fill and keep working the edge. Hit the side too hard with the heat and it's fubarred. LOL