Gdavid
Guru
I would like to hear some opinions of an unusual setup I am considering for the generator and it's alternator.
Current configuration:
The main engine alternator currently charges the starting and house battery bank through an isolator. The onboard battery charger also feeds through this isolator, the charger is never on while the engine is running. There is a battery selector switch enabling the house bank to start the main engine. The boat has a 24v stern thruster with and independent bank and charger, I believe there is also cabling and battery switch allowing the thruster bank to start the main in an extreme emergency (I need to double check this next time I'm at the boat). Ideally the thruster batteries be reconnected into parallel rather than series prior to using it however in this sort of situation the potential damage to the starter may be worth it (depending on the situation).
Considered configuration:
The 4.5kw generator to be installed will share the starting battery for main engine (single screw). What I am considering is running the output from the generator's alternator (small, about 30-45 amp) to the battery isolator and putting it's field wire on a switch so it will only charge when the generator is running but the main is not and the battery charger isn't running either. The sensing wire would go on the house battery bank. My rational is that it doesn't make sense to me to make ac power with the generator only to run it through a battery charger for dc power to maintain the batteries, better to use the alternator and free up ac capacity for other things. An alternative solution would be run the alternator output through a smart battery isolator which would charge the starting battery first and it would then charge both banks once the starting battery is satisfies, this would be simpler to operate and avoid someone having to remember the field wire switch but I don't know how much I trust these smart battery isolators and if would fail in the closed circuit position.
The boat should not have a significant dc draw when at anchor and the house batteries shouldn't be require much charging after a day's running. There is a small inverter that can run the coffee maker or TV but it is rarely used. The boat is primarily used during summer in a humid environment so the generator will be run frequently to power the ac and occasionally the hot water heater.
Any thoughts, am I over complicating things?
Current configuration:
The main engine alternator currently charges the starting and house battery bank through an isolator. The onboard battery charger also feeds through this isolator, the charger is never on while the engine is running. There is a battery selector switch enabling the house bank to start the main engine. The boat has a 24v stern thruster with and independent bank and charger, I believe there is also cabling and battery switch allowing the thruster bank to start the main in an extreme emergency (I need to double check this next time I'm at the boat). Ideally the thruster batteries be reconnected into parallel rather than series prior to using it however in this sort of situation the potential damage to the starter may be worth it (depending on the situation).
Considered configuration:
The 4.5kw generator to be installed will share the starting battery for main engine (single screw). What I am considering is running the output from the generator's alternator (small, about 30-45 amp) to the battery isolator and putting it's field wire on a switch so it will only charge when the generator is running but the main is not and the battery charger isn't running either. The sensing wire would go on the house battery bank. My rational is that it doesn't make sense to me to make ac power with the generator only to run it through a battery charger for dc power to maintain the batteries, better to use the alternator and free up ac capacity for other things. An alternative solution would be run the alternator output through a smart battery isolator which would charge the starting battery first and it would then charge both banks once the starting battery is satisfies, this would be simpler to operate and avoid someone having to remember the field wire switch but I don't know how much I trust these smart battery isolators and if would fail in the closed circuit position.
The boat should not have a significant dc draw when at anchor and the house batteries shouldn't be require much charging after a day's running. There is a small inverter that can run the coffee maker or TV but it is rarely used. The boat is primarily used during summer in a humid environment so the generator will be run frequently to power the ac and occasionally the hot water heater.
Any thoughts, am I over complicating things?