All the electronics involved would be in the box on the back so no grime. Heat also shouldnt really be an issue as the box will be air conditioned. Vibration is an ever present issue but I have isolated the battery and all components so it should be minimal.
I have been hunting around trying to find a contactor I am happy with. Have not found one yet and will keep looking but am interested in what your thoughts would be on this approach.
The Battery protect has an on/off switch. when it is closed the BP is on, open it is off. My plan was to connect this to the electrodacus and it would open the switch at LVD. The problems with this due to the type of load is discussed above and I was going to abandon using the BP.
I am now considering the following:
Generally speaking winching should be done 30 seconds on 30 seconds off as the winch motor can easily overheat if you try winching continuously. I am thinking about building an interlock to prevent the BMS from opening the BP when winching but if battery becomes low while winching, will prevent the next bout of winching protecting the battery protect from destruction and the battery from low voltage.
The + and - for the switch on the BP is connected through the BMS. in-between the BP and the BMS a small normally open relay is inserted connecting the + and - . The coil for this relay is connected to both the spool in and out power connection directly on the winch motor. When winching, the relay will close and ensure that if the BMS opens the circuit, (I can program a LVD delay to make sure this doesnt happen during inrush) the relay will remain closed, the BP switch will remain closed and the BP will not disconnect and destroy itself. When winching stops, the relay opens and if the BMS is open the BP will open when there is no current and prevents any further winching if the battery is low.