Hello I have a new to me 30 year old 27 foot Tiara with twin engines and no generator.
I’d like to set it up for my needs and am looking for suggestions and answers to electrical questions.
My objective is to be able to overnight on the hook and run interior fans, refrigerator, lights, and charge phones off of battery power and still be able to start the engines in the morning.
I’d like to be able to charge any battery from either alternator. Does a battery isolator do this? I’ve seen isolators advertised like PROMARINER 1 ALTERNATOR 3 BATTERY ISOLATOR 70 AMP that seem to do this but its not clear to me if the alternator input is switched to all batteries. For example, if one of my alternators dies will the other still charge all 3 batteries?...if so how would I know if one of the alternators went bad?
I’d also like to be able to switch any battery bank to start either engine in an emergency.
Current setup is:
· Two gas engines
o Mercruiser stern drive 5.7 L V8 Alphas carburated
· Two alternators
o Each tied to it’s own battery
· Two starting batteries
o Port battery also powers windlass
o Starboard battery powers all onboard house loads
· 30 year old permanent battery charger (no inverter)
o Question: is it advisable to leave the charger on while on shore power or will it cook my batteries? Boat sits at the dock during week and runs about 4 to 8 hours every weekend depending on the weather.
· An on / off battery switch for each motor/battery
· An on/off switch for the windlass
· An emergency momentary parallel switch on the dash
My first questions are about batteries. I’d like to leave the house bank on overnight to run things.
1. How much battery do I need to run the fridge, 3 small fans and phone chargers?
2. Is it ok to just let the battery run down overnight till it’s out of power
a. Will that hurt the fridge?
b. Will that hurt the battery?
3. Should I add a dedicated 3rd house bank or beef up one or both of the current two batteries?
4. Should I do a 2 battery setup and make one the starting battery for both motors and one the house bank?
5. What kind of batteries?
a. Lead acid, AGM, other?
b. Run dual 6 volt batteries serialed to equal 12 volts?
c. Deep cycle vs startup for house and starting batteries (I assume there’s a reason for the term “start up”.
My next question is about inverters and isolators
1. When and why would I want to run ACHs vs a multi bank isolator?
2. Should I replace my old technology battery charger with a modern charger/inverter?
a. Does my AC/DC fridge run more efficiently on AC or DC?
b. It would be convenient to power on the electrical outlets for AC phone charging but I can also charge them on DC USB chargers…again is AC or DC more efficient?
c. What’s better inverter for my intended use (or do I need one at all)? Sine Wave VS modified Sine Wave
3. If I upgrade the charger can I leave it on all the time on shore power?
next questions are on battery switches
1. If the answer to the battery question is to set up a 3[SUP]rd[/SUP] house battery bank, what is the recommended battery switch configuration that enables any of the 3 batteries to be switched to start either engine in an emergency
2. This question is easier if two battery banks are used…I’ve seen Blue Sea sells this set up pre configured
Lastly, I plan to install a multifunction battery gauge that measures volts and Amps and can be switched to read up to 3 banks of batteries.
Thanks for reading this far and any recommendations you can offer.
I’m sure to have follow up questions J
I’d like to set it up for my needs and am looking for suggestions and answers to electrical questions.
My objective is to be able to overnight on the hook and run interior fans, refrigerator, lights, and charge phones off of battery power and still be able to start the engines in the morning.
I’d like to be able to charge any battery from either alternator. Does a battery isolator do this? I’ve seen isolators advertised like PROMARINER 1 ALTERNATOR 3 BATTERY ISOLATOR 70 AMP that seem to do this but its not clear to me if the alternator input is switched to all batteries. For example, if one of my alternators dies will the other still charge all 3 batteries?...if so how would I know if one of the alternators went bad?
I’d also like to be able to switch any battery bank to start either engine in an emergency.
Current setup is:
· Two gas engines
o Mercruiser stern drive 5.7 L V8 Alphas carburated
· Two alternators
o Each tied to it’s own battery
· Two starting batteries
o Port battery also powers windlass
o Starboard battery powers all onboard house loads
· 30 year old permanent battery charger (no inverter)
o Question: is it advisable to leave the charger on while on shore power or will it cook my batteries? Boat sits at the dock during week and runs about 4 to 8 hours every weekend depending on the weather.
· An on / off battery switch for each motor/battery
· An on/off switch for the windlass
· An emergency momentary parallel switch on the dash
My first questions are about batteries. I’d like to leave the house bank on overnight to run things.
1. How much battery do I need to run the fridge, 3 small fans and phone chargers?
2. Is it ok to just let the battery run down overnight till it’s out of power
a. Will that hurt the fridge?
b. Will that hurt the battery?
3. Should I add a dedicated 3rd house bank or beef up one or both of the current two batteries?
4. Should I do a 2 battery setup and make one the starting battery for both motors and one the house bank?
5. What kind of batteries?
a. Lead acid, AGM, other?
b. Run dual 6 volt batteries serialed to equal 12 volts?
c. Deep cycle vs startup for house and starting batteries (I assume there’s a reason for the term “start up”.
My next question is about inverters and isolators
1. When and why would I want to run ACHs vs a multi bank isolator?
2. Should I replace my old technology battery charger with a modern charger/inverter?
a. Does my AC/DC fridge run more efficiently on AC or DC?
b. It would be convenient to power on the electrical outlets for AC phone charging but I can also charge them on DC USB chargers…again is AC or DC more efficient?
c. What’s better inverter for my intended use (or do I need one at all)? Sine Wave VS modified Sine Wave
3. If I upgrade the charger can I leave it on all the time on shore power?
next questions are on battery switches
1. If the answer to the battery question is to set up a 3[SUP]rd[/SUP] house battery bank, what is the recommended battery switch configuration that enables any of the 3 batteries to be switched to start either engine in an emergency
2. This question is easier if two battery banks are used…I’ve seen Blue Sea sells this set up pre configured
Lastly, I plan to install a multifunction battery gauge that measures volts and Amps and can be switched to read up to 3 banks of batteries.
Thanks for reading this far and any recommendations you can offer.
I’m sure to have follow up questions J