A tale of battery cables

I made a similar die I use in a press. I still try and sweat some solder in the ends and then slide some shrink tubing over them.

There is much controversy about the use of solder in high current connections. I follow the faith of of good solder less crimps. Solder introduces a less conductive metal, the soldering temperature messes with copper hardness near joint. It was apparent that strand failures were experienced in the cables, were likely related to solder process on lug end, and lead cast on the other.