I installed this battery switch. I favor hefty purely mechanical switches. No chance for even small current drains, no latching relays, no need to reach far back into the battery compartment to the negative terminal, etc.
This one from Fastronix (#303-001) supposedly can handle 1000 amps intermittently and 180 amps continuous. It is quite beefy, but fits in the compartment on the right hand side.
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