Relay Isolator?

[LosIsATool 5,000+ posts]

I'm going to be installing a 2nd battery soon I have a 200 amp circuit breaker between the engine bay and the firewall do I need another cb or fuse before the 2nd battery?

Dont run circuit breakers under the hood. You dont want them exposed to elements

 

[agarabaghi 10+ year member]

They will be fine... Or pick up some marine ones