Re: Battery terminal question
Marine grade battery terminal ends tend to be brass or thick copper, the battery post clamps tend to be solid brass also...you could use automotive lead ones but they don't take vibration well or last as long. Brass battery clamps have wingnut terminals which are usually required anyway.
As for cables they make a special tinned multistrand wire for marine applications as JB mentioned that is designed for the purpose. You need this cable if you are in any kind of salt water...period. However if all your boat is ever going to see is fresh water the automotive stuff will last quite a few years, many boats from the factory in the 80's only had regular non-tinned wire in their boats and they are still on the water. When I re-did the wiring on my boat the regular grade wire had corroded at the terminal connections but 1 inch back it was still bright clean copper, I re-terminaled and crimped all the wires and soldered the connections this time as well as sealed them with silicone grease and shrink tubing...it might possibly last longer than the boat since the factory crimps lasted 22 years. I think most wiring problems in a boat originate at the terminal connections and tinned wire makes a longer lasting connection if it is only crimped.
Battery cable of 4-6 gauge is where it gets expensive for the tinned stuff, I compromised and bought welding cable (its jacket is meant for wet areas) and soldered, crimped and shrink tubed the connections, it is essential these connectors are crimped since solder has resistance different than copper, it is OK to seal the crimped connection with solder...but it must be crimped. The 6 gauge battery cable leading to the front of my boat for the trolling motor was still fine and it was not tinned.
If you compare wire you will notice the marine grade wire is thick wire strand not fine, this type of wire is meant for high vibration handling...the thin wire strand like welding cable is OK if it is supported. In short you can do whatever you want with wire in a boat if you understand the limitations of non-marine grade wire and how it differs from the marine grade...you make the decision of what to use and where.
If you want to just wire the darn thing and not worry about it...get the tinned wire and some heavy duty marine grade wire terminals (they are thicker and heavier) and crimp away...you can't go wrong with that setup.
