Battery Cables...

I'm replacing the battery cables on my Johnson 200 HP as I'm adding an extra battery, the cable that I have on right now is a ribbon cable which carries the POS and NEG cables together, but I noticed that the black cable stated splitting from the ribbon and part of the wire is slightly exposed and showing wire (on the NEG) my boat stays in dry storage, but still have to deal with the moisture so the cables is showing corrosion, I started to notice that the cable heats up too, not bad, I think is just during the cranking, either way needs to be replaced, I’m just trying to see what are the best gauge I should select, I will be running about 8’ of POS and NEG cable, I was thinking about 4 gage... what you guys think??? Also what could be causing the cable to heat up??? I think that is the reason it started to split...Would gauge 2 or 1 be an over kill??? I got 6’ of 4 gage between the two batteries…the cables to be replaced are the ones that go straight from the battery to the starter.

Corrosion causes the Cable to become a Resistor. You do need to clean or replace cables before you kill something in your charging system.
I didn't understand your post.
Draw a clear picture and post that.

Terminal ends from Chiana, labeled Copper, are 90% Tin and 10% Copper food coloring.
Pay a little more and get better Terminal ends.

Hi Nick....how's things?

One thing to be sure of.....most all boat wiring has the individual strands inside the insulation tinned, that is, there is a coating of solder on the copper wire.
If you just go get 2 gauge welding cable, for example, the wire will be bare copper under that insulation. It will turn green very quickly.

I have found great deals on OEM J/E battery cables on eBay. I think about 30 bucks is a great deal.