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Sailboat power installation

Tom Long

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Aug 29, 2021
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I am in the process of outfitting a 36’ sailboat for cruising. I was planning on installing a 400 watts wind generator, 600 to 800 watts of solar panels and be able to charge the house bank with the alternator when needed, I will install 5 100AH lithium iron batteries as the house bank. Keep the standard lead acid battery for the starting battery. I have read about duel power controllers that the solar panels and wind generator hook up to, but have not seen a controller for the alternator, I have seen 12v dc to dc chargers for charging the lithium batteries. Does anyone make a controller that a alternator, a wind generator and a solar array can hook up to? If I go with the DC to DC charger for use with the alternator and a solar/wind controller will there need to be a switch were the house bank is charged by one system at a time?
I am new to the solar/wind generating process and could use some help designing the system
Thanks
Tom
 
Welcome to the forum.

Does anyone make a controller that a alternator, a wind generator and a solar array can hook up to?
I am not aware of a controller that will do alternator, wind and solar. (What controller are you looking at for Wind + Solar?).

If I go with the DC to DC charger for use with the alternator and a solar/wind controller will there need to be a switch were the house bank is charged by one system at a time?
There is no need for a selector switch, you can have two separate charge control devices charge the same battery bank at the same time.
Ideally, all the controllers will all be set to identical charge profiles.... but even that is not a requirement.
 
I am not aware of an all-in-one charger like that. You can get a combination shore charger and MPPT controller (renogy) but it isn't what I would recommended, as it isn't the best shore charger or the best mppt solar controller.

The wakespeed WS-500 alternator regulator will talk to other devices via can bus, so while it isn't an all in one, they can cooperate. I don't use a CAN but for my charging systems, however. I do _highly_ recommend this regulator for charging Lithium. It has a temp sensor and will deliver the maximum output your alternator can provide without overheating, and is much easier to program than the Balmar alternator.

As a full time cruiser, I can offer some other advise. You will not get 400W from the wind generator. That money is better spent on solar. If you have money to burn, wind is nice only because you get something at night and on cloudy days. But overall, the contribution is small.

500Ah of Lithium is very large. Most 36ft cruising boats have lead batteries in the 450Ah range (4 6V T-105 batteries or equivalent). Of that, only 200Ah is useable. With Lithium it is nearly all useable, so you will have more than double that. A typical boat that size might use 150Ah per day, and 800W of solar will provide about 250Ah per day. So it will take up to 5 days to charge that battery. 500Ah of Lithium is awesome, so go for it if you can. But Lifepo4 is expensive and you might consider that money elsewhere.
 
On a sail boat you need a charger controller for every panel due partial shadowing, changes of the solar angel and so on .
And on long trips you will have redundancy .
And do not spend your money on a wind generator , invest that money in a real good installation.
Change out the stock engine generator for a real good one with charge controller and generator protection, look at Balmar generators the have a kit for every engine, lithium is so much better on a sail boat special with a good engine generator.
Solar and a Balmar and Lithium and you will never run out of power.
I spend a lot of time to design a system on our future long range sailboat but we have changed plan due a fast changing world .
A full electric sailboat , no gas ,electrical cooking, water maker and so on.
You can make water and power but not Diesel fuel.
Never ever buy forced ventilated cheap electronics on a sail boat in a salt water enviroment, it WILL fail on you , just a matter of time
 
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How did you come up to these enormous sizes of both solar and LFP?

I can’t see how/where you would fit 600-800 watts of solar panels on a 36 ft sailing yacht?

And your LFP size should be sized to survive the night plus one extra cloudy day.
LFP loves to cycle, so try to size your LFP bank to your daily consumption plus a bit extra.
 
I am in the process of outfitting a 36’ sailboat for cruising. I was planning on installing a 400 watts wind generator, 600 to 800 watts of solar panels and be able to charge the house bank with the alternator when needed, I will install 5 100AH lithium iron batteries as the house bank. Keep the standard lead acid battery for the starting battery. I have read about duel power controllers that the solar panels and wind generator hook up to, but have not seen a controller for the alternator, I have seen 12v dc to dc chargers for charging the lithium batteries. Does anyone make a controller that a alternator, a wind generator and a solar array can hook up to? If I go with the DC to DC charger for use with the alternator and a solar/wind controller will there need to be a switch were the house bank is charged by one system at a time?
I am new to the solar/wind generating process and could use some help designing the system
Thanks
Tom
I would not spend a nickel on wind. Invest in solar, batteries, and alternator.
 
How did you come up to these enormous sizes of both solar and LFP?

I can’t see how/where you would fit 600-800 watts of solar panels on a 36 ft sailing yacht?

And your LFP size should be sized to survive the night plus one extra cloudy day.
LFP loves to cycle, so try to size your LFP bank to your daily consumption plus a bit extra.
645 watts of solar fits on a C&C 34. It uses up my entire bimini top, but what else am I going to use that for?

Don't see much problem with a larger bank. You can always use more power if you want to cycle your batteries.
 
How did you come up to these enormous sizes of both solar and LFP?

I can’t see how/where you would fit 600-800 watts of solar panels on a 36 ft sailing yacht?

And your LFP size should be sized to survive the night plus one extra cloudy day.
LFP loves to cycle, so try to size your LFP bank to your daily consumption plus a bit extra.
If i can remember well, best cycling between 20 and 90 % that gives you 70% capacity for long battery live span and you can occasional go deeper in discharge max till 10% !
 
How would you manage this?
Discharge ( the most important one) can be set in your inverter or
Charge/discharge can be set in your charge controller/battery management system .
I would have split up the power system into an essential group and a group for the rest
The essential group would have a spike filter to protect the expensive navigation electronics
 
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Discharge ( the most important one) can be set in your inverter or
Charge/discharge can be set in your charge controller/battery management system .
What voltage indicates 20% SOC?
What voltage indicates 90% SOC?
Are you factoring an offset for charge/discharge current?
 
check your battery specs .
Look at the charge and discharge graphs
I'm asking you what voltages you use.
I have my own charge/discharge regime.
I'm particularly interested in whether you factor a current offset.
 
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I'm asking you what voltages you use.
I have my own charge discharge regime.
I have a land based grid tied 3,5 KW 48 V system with AGM as emergency back up.
My voltages are absolute NOT suitable for you.
I deep discharge my AGM only in an emergency situation and cut of under load at 46,4 V ( it happens only once a year or so )
Maintenance cycling is partial and controlled by me ( first an heavy load for a short time than a little rest and than a longer discharge till 12,2 V
Max charging is at 25 A 3 stage AGM curve , twice a year )
My battery back up is more like an extended UPS and keep the solar working if there in no grid, for longer grid outs i start up the 2 KW smart inverter more or less silent generator , charging the batteries and power the house .
Last storm we were out of grid for more than 24 hours and at day time no sun, the gen set kept all perfectly up, no issues wit pumps and so on.
Batteries are now 8 years old and still in good condition
Batteries are under control by a Outback 80 controller and we are using an Outbak inverter
 

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I have a land based grid tied 3,5 KW 48 V system with AGM as emergency back up.
My voltages are absolute NOT suitable for you.
I deep discharge my AGM only in an emergency situation and cut of under load at 46,4 V ( it happens only once a year or so )
Maintenance cycling is partial and controlled by me ( first an heavy load for a short time than a little rest and than a longer discharge till 12,2 V
Max charging is at 25 A 3 stage AGM curve , twice a year )
My battery back up is more like an extended UPS and keep the solar working if there in no grid, for longer grid outs i start up the 2 KW smart inverter more or less silent generator , charging the batteries and power the house .
Last storm we were out of grid for more than 24 hours and at day time no sun, the gen set kept all perfectly up, ni issues wit pumps and so on.
Batteries are now 8 years old and still in good condition
My system is an an online UPS with a 280 amp hour@25.6 volt LFP battery.
I charge at 1:00am with a charge voltage of 27.4 volts and a tail current of 12 amps.
I float at 26.4 volts.
If the mains power is unavailable my inverter disconnects at 24.8 volts.
Testing shows the cell delta will be under ~30mv even at full load.
 
My system is an an online UPS with a 280 amp hour@25.6 volt LFP battery.
I charge at 1:00am with a charge voltage of 27.4 volts and a tail current of 12 amps.
I float at 26.4 volts.
If the mains power is unavailable my inverter disconnects at 24.8 volts.
Testing shows the cell delta will be under ~30mv even at full load.
When i build this installation LPF was a way to expensive and NOT available for me , the transport cost from the USA was also ridiculous high, so used Rolls AGM.
You are in the know,
I have zero maintenance , only cleaning the panel in the dry season to get rid from some dust on the panels
the outback Latin America stuff is doing a great job, it controls everything automatically after a initial setup .
 
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