battery isolator

I am updating my battery system on the boat (1989 Catalina 30); I’ve included a crude diagram of it currently. I want to add an Isolator to the mix to keep my starting battery from draining accidentally and I want to add a Battery monitor. I am not sure where to wire each of these and how. I’ve...

I have a house bank and a starting bank, both of which can be isolated using a common four-position battery switch (OFF, 1 [house], BOTH, 2 [start]). I have solar connected to a Victron SmartSolar charge controller which has its negative lead connected to the main DC negative bus (to which both...

I am wondering if anyone has an idea of what the different relays and fuses are in the house battery compartment? (see picture) from left to right 1). 2 inline glass fuses, 2. 20 amp fuse, 40 amp fuse, 12v 50 amp 5 pin rekey, 12v 25 amp 5 pin relay. What I'm really having problem is that...