Two battery sport cruiser..best way to use the Perko Switch?

[Tonka Boater]

Lots of good info in this thread....

For what it's worth, I have 2 batteries and a switch in my current boat. When I launch the boat I set it to battery 1 then start the boat and let the engine warm while I park the truck/trailer (this also allows battery 1 to charge for a bit). Before I get underway I switch to battery 2 to ensure it gets fully charged while I motor to my destination -- usually anchored out. I use battery 2 to power the electronics while the boat's not running. At the end of the day I switch back to battery 1 because I know it has a full charge and I start the engine. I let it idle on battery 1 while I get everything stowed and pull the anchor. Before I get underway again I will switch back to battery 2 to charge it on my way back to the marina or boat launch.

Forgot to mention this -- when I had my 280DA parked in a slip I would set the switch to ALL while connected to shore power because we would often hang out on the boat at the marina. Setting the switch to OFF would kill power to the cabin lights and stereo even while connected to shore power. The kids liked to sleep on the boat at the marina so we needed the amenities to work.

 

[Tim Jodice]

My port motor has just one battery that does nothing but start the port motor. My starboard motor has two batteries, and they power everything that is 12 volt on the boat.
I run with the battery switch in the "Both" position. When I drop the hook, I switch to either "1" or "2". Then switch back to "Both" before I start that motor.
At my home dock I'm plugged in to electric, so I leave the switch in the "both" position.

Mine is the same way. One battery and an on - off switch for the port engine that does nothing else but power/charge that engine and it's associated accessories. 2 batteries with a 1-2-both - off switch for the starboard engine that power/charge that engine and it's accessories plus the house. They wire in a cross over switch to start the starboard engine with the port battery in case you kill the starboard batteries. Now we have a port alternator that only need to recover from what took to start the engines and then run the port engine while the starboard alternator is recharging 2 dead batteries and running the engine. I would think it would make more sense to have a port - house - starboard battries and have the alternators charge there own batteries first then work together to charge the house battery(s). Sea Ray is not stupid so there is a reason they wire it like this. Can someone educate me?