Repair your battery with the melted post by using a self-tapping screw right into the lead to fasten your battery cable. I've had several carts with this repair last for years. A better option is to screw in a stainless steel "shelf-hanger". This is a bolt with screw threads on one end & machine threads on the other. I have a tool to install these with my DeWalt impact driver. I think you could run a nut down then wrench the bolt in by hand. The advantage is you can remove the cable for cleaning/replacement and not loosen the bolt in the lead. Often the self-tapping screw option will yield a corroded screw head that you can't get out.