Had a remote controlled high current battery isolator fail on my narrowboats 12 volt 9 hp bow thruster installation. The isolators M8 battery cable studs had got so hot they compromised the material that held them captive and caused an open circuit in this case. This despite battery cable fixings remaining tight and isolators 1000 amp starter current rating.
I remember being a bit miffed at the time as had deliberately over engineered the boats electrical installation as a whole, but this just served to highlight the weakest link. Changed isolator for next size up with M10 studs, 2500 amp momentary rating and 600 amp continuous. In fairness I did blow the thrusters 600 amp fuse once when its prop was temporarily fouled.
