All circuit breakers, whether DC, or AC as in your home panel, degrade with each use, and will trip at a lower amperage than rated for with a bunch of operations.I have a 185 amp breaker. Thought being I rather trip the breaker as a clue to use a snatch block and avoid overheating a winch motor running at max amps. It has never tripped yet. On a side note, after three years, the breaker has started to trip periodically, without any winch use, just radio and PS (straight line driving). Hit the reset and it works ok for another few weeks. Maybe age related issue?