I've got a used boat. OK, OK, it's an OLD boat. Built in 1980. I decided to dump the two old 100ah FLA house batteries for a single lithium 125ah. The lithium battery does not have battery posts but instead you bolt the cables to the battery. PITA because now I have to remove the negative cable from the house and start batteries and the engine block. Need to change the clamp-on terminal for a lug. While removing the negative cable, I felt something strange on the insulation. 
Oh, the insulation is completely gone and bare wires are visible. The insulation that is left is completely cooked and flaking off. I suspect that a previous owner had a hard time starting the engine and ran the starter way too long. And I went from modifying the negative cable to replacing all the battery cables. How I and the previous owners managed to not burn up the boat, I'll never know.

Oh, the insulation is completely gone and bare wires are visible. The insulation that is left is completely cooked and flaking off. I suspect that a previous owner had a hard time starting the engine and ran the starter way too long. And I went from modifying the negative cable to replacing all the battery cables. How I and the previous owners managed to not burn up the boat, I'll never know.