In the auto electric business there is always a lot of questions about battery cables. What size to use, should they be soldered, what’s the difference between welding cable and battery cable, and the list goes on.
First of all see the wire gauge chart to determine what size to use. Remember 6 volt cable is bigger than 12 volt cable in automotive applications.
The biggest Misunderstanding about battery connections is soldering. NEVER solder cable connections! Solder makes one big joint for the current to travel through and soldering introduces a 3rd metal to the equation. The current travels on the out side of the strands of cable, so welding cable is a better conductor than battery cable because welding cable has more strands of wire for the same given size for better current travel. The crimp connection done with the right tool has always been the best way to make or fix a cable. No manufacture of any equipment or automobile has ever soldered cable connections. Having the knowledge to do the job the right way takes out the guess work. The most powerful batteries are no good unless that power can get to the starter. Larry H