Interesting discussion on dual batteries. I have a camper I pull and to charge the batteries there is just a wire running from my car's battery to the trailer. That charges the deep cycle batt on the trailer. To isolate the trailer there is this simple unit from the camper dealership for about $5 that automatically isolates the batteries when I take the keys out of the ignition. I found a circuit in the fuse box that produces energy when I start the car and quits when I turn it off. I simply connected a wire from the isolation unit I purchased to that fuse (yeah, I just stuck the wire in there, nothing professional) and now my camper won't drain my car's batt when the engine is off. Just to make sure there isn't any confusion to what I wrote. The positive cable from the batt on the car provides power to charge the batt on the camper. The wire from the fuse box just closes the relay to allow power to move from the car's batt to the camper's batt. The fuse box isn't providing the large amperage to charge anything.
Can't you just do a simple setup like this for your boat? It seems so simple. How is the boat's alternator any different than my cars? All I want to to with the 2nd batt is run some lights and my stereo. Batt goes dead, so what? Just fire up the mercruiser and charge it back up.
I say simple because I don't know the limitations of the system. However my car and camper hasn't caught on fire yet. ha! Seriously though, coudn't I just do this same set up for my boat?
Can't you just do a simple setup like this for your boat? It seems so simple. How is the boat's alternator any different than my cars? All I want to to with the 2nd batt is run some lights and my stereo. Batt goes dead, so what? Just fire up the mercruiser and charge it back up.
I say simple because I don't know the limitations of the system. However my car and camper hasn't caught on fire yet. ha! Seriously though, coudn't I just do this same set up for my boat?