Join Date: May 2009
Location: Palm Island Miami Beach
Thanked 1 Time in 1 Post
Rep Power: 8
I use a Blue Sea Isolator to do this.
Start with your starting battery hooked to the starter and the alternator, nothing else, with the negative to the engine block.
connect a second hot from the starting batt to the A side of the isolator.
The house bank should have a pos to the accessory panel, a neg to the engine block, and then add a pos to the B side of the isolator.
Start the motor, the starting battery comes up to 13.5, when the starting battery is charged, the isolator senses this and couples the house bank automatically, and it charges,
When you turn the motor (or shore power charger for that matter) off, the isolator senses this, and uncouples the house bank.
The test to see if it's working is very simple.
Invite a bunch of friends aboard, drink a ton of tequila, fall asleep with all of the lights etc, on.
Wake up to a weird buzzing sound, made by the inverter that's attached to the house bank, with all the lights really dim and the stereo off.
Hit the key, and your motor will spring into life, take a minute to top off your starting bank, then automatically couple your house bank, and start charging it. You're back in business.