- Jun 28, 2021
Excellent point about a weakness of the wire interconnect approach. I will try to mitigate it by using top quality wire, and dipping the ends as you described. Lucky for me I have a pretty modern boat, with a dry bilge, and my battery box area tends to say quite clean and dry. I’ll also run my system under max rated load once a year and look for heat in connections.The issue is never the correctly done crimp!
The issue is the cable jacket! The jacket is sealed to the lug - heatshrink tube with self melting glue inside is typical - will always fail. In your picture where the cable is subject to a tight bend radius they will fail faster.
If you go with tinned copper this is not a big deal for "dry land" applications; the cables can live for many years without issues. For bare copper it will oxidize starting at the cable ends just past the nice crimps and moving inwards. Eventually the strands break, resistance goes up, and the cycle accelerates until you have a failure.
The issue is on a boat even the best tinned copper cables do not last long once salt water gets under the jacket. It then quickly corrodes the fine strand wiring causing high resistance and eventually failure. Once it starts under the jacket it is impossible to stop - replacing the cable is the only option.
I've seen all sorts of things used to prevent this and about the best is Permatex liquid electric tape in which you mask off the lug contact areas and then dip the entire end into the material to about 1.5 inches up the cable and then let it hang dry. Depending on cable size it might need several dip, dry, dips to get the desired thickness. This will last a good many years. But it is a slow and labor intensive process to do correctly.