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New battery/inverter-charger/solar setup questions for a sailboat

mjmcpo

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Just getting into this and have a limited knowledge base so I'm looking for some guidance on a future upgrade. Just ordered two of the marine grade 206Ah SOK batteries that will be installed on my sailboat as the house bank. Planning to keep one of my lead acid as a start battery. Have also ordered a Victron Multiplus 12V 3000 watt inverter/charger, the Victron Digital Multi control, the Victron 500A SmartShunt, the Victron VE. Bus smart dongle and a Sterling 12v Alternator protection device.

Hoping to add two 180 watt rigid solar panels, one 100 watt flexible panel and one 50-ish watt flexible or rigid panel.

My questions are: Any benefit to keeping the start battery completely separate by using a battery to battery charger and charging only from the alternator? Or easiest to connect to the inverter/charger and use the trickle charge feature. I have a relatively small 18 hp diesel engine with a stock alternator. Not sure what size it is.

Regarding the solar, can I use one MPPT charge controller for all of the panels or would it be better to split the panels between separate controllers. Any size suggestions. I have a single Victron MPPT 100V/50A controller in my shopping cart at the moment.

Lastly, is it helpful or necessary to have one of the battery monitors like the BMV700/712 or can I get by using BT and my phone or tablet for monitoring?
Please don't hesitate to comment or make suggestions if I'm completely overlooking something. As I mentioned, I'm pretty green at al of this. Thanks in advance!
Matt


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My questions are: Any benefit to keeping the start battery completely separate by using a battery to battery charger and charging only from the alternator?
I recommend that you keep the lead-acid and have A DC-DC converter. However, you need to find out what the rating of the inverter is and keep the load from the house battery at ~50% of the inverter rating.

If you try to use the house battery for the starter you will need to address a couple of things:

1) Will the LiFePO4 batteries be able to supply the cranking current for the starter? (There is a good chance they won't)
2) The regulator on the alternator needs to be smart enough to keep it from burning itself out when charging the LiFePo4 batteries with their really low internal resistance.
Regarding the solar, can I use one MPPT charge controller for all of the panels or would it be better to split the panels between separate controllers.
Generally speaking, it is a bad idea to have different types of panels on the same controller. I would recommend different controllers for each type of panel. (I assume you are planning on 3 different panel types due to space and mounting constraints.

Any size suggestions. I have a single Victron MPPT 100V/50A controller in my shopping cart at the moment.
That is going to depend on the specifics of the Panels that will be hooked up.
is it helpful or necessary to have one of the battery monitors like the BMV700/712 or can I get by using BT and my phone or tablet for monitoring?
That is a personal preference. I really want to be able to glance at a meter and see the state of charge. Pulling out my phone, opening the app, and then reading SOC is a PITA to me. (But I am an old Luddite). A lot of people (Including Will) seem perfectly happy with pulling out the phone.
 
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I recommend that you keep the lead acid and have A DC-DC converter. However, you need to find out what the rating of the inverter is and keep the load from the house battery at ~50 of the inverter rating.

If you try to use the house battery for the starter you will need to address a couple of things:

1) Will the LiFePO4 batteries be able to supply the cranking current for the starter? (There is a good chance they won't)
2) The regulator on the alternator needs to be smart enough to keep it from burning itself out when charging the LiFePo4 batteries with their really low internal resistance.

Generally speaking, it is a bad idea to have different types of panels on the same controller. I would recommend different controllers for each type of panel. (I assume you are planning on 3 different panel types due to space and mounting constraints.


That is going to depend on the specifics of the Panels that will be hooked up.

That is a personal preference. I really want to be able to glance at a meter and see the state of charge. Pulling out my phone, opening the app, and then reading SOC is a PITA to me. (But I am an old Luddite). A lot of people (Including Will) seem perfectly happy with pulling out the phone.
Thanks for the thoughtful feedback.
 
what we’re planning for our 27’ sailboat is to replace our stock alternator with an externally regulated unit and use a wakespeed ws500 regulator with it. This will tie in to our victron and BMS, and should make for a good solid integrated system. For our starting battery, we’ll probably use a small starting battery (think Mazda Miata sized) and maintain it with an 18A dc:dc charger.
 
If your panels are all rated at the same voltage AND they are 24 volt panels you could put them in parallel and be ok with one charge controller. This does require more fuses/breakers though. Due to slight differences in voltages It wouldn't be quite as efficient as splitting them between various charge controllers, but it would be simpler and I think nearly as good.

However, if you've already purchased panels and they are 12 V I wouldn't recommend putting them all in parallel because the MPPT won't start charging until you have like 75% plus output so they won't do much on cloudy days and early morning/late afternoon.

Curious to know how you like the SOK marine battery, that seems like a very nice (and reasonably priced) product.

For monitors, I really like the GX system where I can see battery SOC, how many watts are coming in from solar and going out to DC or AC loads all on one nice little screen. It's very fancy. But yes, if you have a fairly simple boat setup you could also see this on your phone and save $. I have the BM-712 too but never look at, just the GX screen.

If it were just me I would go with the simple bluetooth phone system. I would know what I had turned on at any moment so wouldn't really need the screen much anyways. However, I have a wife and two kids and we live aboard. Who knows what all is being run at any one time? My wife used the electric pressure cooker for supper yesterday. It ran 3 hours. Battery SOC was still 84% when supper was ready, which is great, but in this type of environment I appreciate being able to see what's going on with a glance as I walk past the screen on our boat.
 
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If your panels are all rated at the same voltage AND they are 24 volt panels you could put them in parallel and be ok with one charge controller. This does require more fuses/breakers though. Due to slight differences in voltages It wouldn't be quite as efficient as splitting them between various charge controllers, but it would be simpler and I think nearly as good.

However, if you've already purchased panels and they are 12 V I wouldn't recommend putting them all in parallel because the MPPT won't start charging until you have like 75% plus output so they won't do much on cloudy days and early morning/late afternoon.

Curious to know how you like the SOK marine battery, that seems like a very nice (and reasonably priced) product.

For monitors, I really like the GX system where I can see battery SOC, how many watts are coming in from solar and going out to DC or AC loads all on one nice little screen. It's very fancy. But yes, if you have a fairly simple boat setup you could also see this on your phone and save $. I have the BM-712 too but never look at, just the GX screen.

If it were just me I would go with the simple bluetooth phone system. I would know what I had turned on at any moment so wouldn't really need the screen much anyways. However, I have a wife and two kids and we live aboard. Who knows what all is being run at any one time? My wife used the electric pressure cooker for supper yesterday. It ran 3 hours. Battery SOC was still 84% when supper was ready, which is great, but in this type of environment I appreciate being able to see what's going on with a glance as I walk past the screen on our boat.
Thanks for the feedback. Just ordered the batteries the other day so still waiting on them to arrive. The reviews sound promising. Can let you know how they work out once I get out cruising.
 
You really need to sketch out how you want to wire this up, as there are several ways that will work well, and other ways that will not work well. So, sketch your ideas and most them. I also recommend working up an energy budget. I have enough solar to run a fridge, a freezer, watch a couple movies per day on a flatscreen TV, and cook a meal on an induction cooker. So, alternator charging and generator charging are not really important for me to over-engineer.

I have the BMV-712. I glance at the meter many times all day long. I use bluetooth if I want to know anything other than the % SOC.
The alternator should be connected to the LA start battery. That can be paralleled to the LFP, connected with a relay (ACR) when charging, or via DCDC charger. Pros and cons to each, and some precautions that may need to be taken. My system uses a DCDC charger, and I prefer that method.

If you upgrade your alternator, you can connect directly to the LFP. With some money and not too much effort you could charge your LFP at about 70A with an alternator this way. Any more than that will require a serpentine belt.

You definitely want multiple MPPT controllers. It can work with one, but 2 (or even 3) will work better. Exactly how you configure it will depend on how they are positioned and how they experience shading. An example (this is atypical but how I have it on my boat). I have 4 100w panels connected to 1 controller. 2 of those on each side of the boat. Since one side of the boat will often be in the shade, I have the 2 panels on each side in series, but then the 2 sides in parallel. That goes to my first MPPT controller. I have 3 additional panels, (80W, 90W, and 100W), in more random places where I could make them fit. Those 3 panels are in parallel on a second controller.
 
You really need to sketch out how you want to wire this up, as there are several ways that will work well, and other ways that will not work well. So, sketch your ideas and most them. I also recommend working up an energy budget. I have enough solar to run a fridge, a freezer, watch a couple movies per day on a flatscreen TV, and cook a meal on an induction cooker. So, alternator charging and generator charging are not really important for me to over-engineer.

I have the BMV-712. I glance at the meter many times all day long. I use bluetooth if I want to know anything other than the % SOC.
The alternator should be connected to the LA start battery. That can be paralleled to the LFP, connected with a relay (ACR) when charging, or via DCDC charger. Pros and cons to each, and some precautions that may need to be taken. My system uses a DCDC charger, and I prefer that method.

If you upgrade your alternator, you can connect directly to the LFP. With some money and not too much effort you could charge your LFP at about 70A with an alternator this way. Any more than that will require a serpentine belt.

You definitely want multiple MPPT controllers. It can work with one, but 2 (or even 3) will work better. Exactly how you configure it will depend on how they are positioned and how they experience shading. An example (this is atypical but how I have it on my boat). I have 4 100w panels connected to 1 controller. 2 of those on each side of the boat. Since one side of the boat will often be in the shade, I have the 2 panels on each side in series, but then the 2 sides in parallel. That goes to my first MPPT controller. I have 3 additional panels, (80W, 90W, and 100W), in more random places where I could make them fit. Those 3 panels are in parallel on a second controller.
Thanks for the info. I have a relatively new diesel 18 hp engine on the boat that already has a serpentine belt and a decently sized 115amp Mitsubishi alternator. If I go the DC/DC charger, can you recommend what size I would need? Will have one SLA start battery and two 206 Ah lithium for house bank. I’m planning to use all Victron components.
 
Thanks for the info. I have a relatively new diesel 18 hp engine on the boat that already has a serpentine belt and a decently sized 115amp Mitsubishi alternator. If I go the DC/DC charger, can you recommend what size I would need? Will have one SLA start battery and two 206 Ah lithium for house bank. I’m planning to use all Victron components.
My rule of thumb is to never design for drawing more than 50% of the rated current of the alternator.
 
My rule of thumb is to never design for drawing more than 50% of the rated current of the alternator.
With advanced regulators such as the Wakespeed WS500, you can let it go as hard as it can within the temperature limits. If you need to limit the output to save HP for propulsion, that can be programmed in as well.
 
With advanced regulators such as the Wakespeed WS500, you can let it go as hard as it can within the temperature limits. If you need to limit the output to save HP for propulsion, that can be programmed in as well.
Yes.... I failed to mention that and should have. Sorry for any confusion. If the alternator is paired with a smart regulator and proper temp sensors, it will throttle back the output if the inverter is getting too hot. My rule of thumb applies to the more traditional inverters and controllers that don't have the capabilities needed to prevent the inverter from burning itself out trying to satisfy the demand. (I do not know if the Mitsubishi mentioned has these capabilities).
 
Yes.... I failed to mention that and should have. Sorry for any confusion. If the alternator is paired with a smart regulator and proper temp sensors, it will throttle back the output if the inverter is getting too hot. My rule of thumb applies to the more traditional inverters and controllers that don't have the capabilities needed to prevent the inverter from burning itself out trying to satisfy the demand. (I do not know if the Mitsubishi mentioned has these capabilities).
I believe my Mitsubishi alternator is a standard internally regulated version. That’s why I’m thinking DC-DC option for now.
 
Thanks for the info. I have a relatively new diesel 18 hp engine on the boat that already has a serpentine belt and a decently sized 115amp Mitsubishi alternator. If I go the DC/DC charger, can you recommend what size I would need? Will have one SLA start battery and two 206 Ah lithium for house bank. I’m planning to use all Victron components.
If I was you, I’d take the alternator to an alternator shop and have them modify it for external regulation. It’s a pretty easy modification for them to make. There are significant benefits to having something smarter run your alternator.

Aside from controlling it WRT temperature, you can do things like phase in alternator power above a certain RPM. For small engines like ours (I have a 1GM10), I’m going to set things up so the Field current goes to 0 when the engine is below 1000rpm. That will make idle and low speed maneuvering (in the marina, retrieving the anchor) much better without the alternator drag.

Another thing is that something like the WS500 will integrate with your Victron system, and let you run DVCC. As your batteries approach fully charged, it will tail off the alternator output as requested by the system. When they go full, it will go into a 0A mode, where it’s adjusting itself to keep its output matched to your house loads, and the battery charge current at 0.

Definitely the optimal way to go, imho.
 
If I was you, I’d take the alternator to an alternator shop and have them modify it for external regulation. It’s a pretty easy modification for them to make. There are significant benefits to having something smarter run your alternator.

Aside from controlling it WRT temperature, you can do things like phase in alternator power above a certain RPM. For small engines like ours (I have a 1GM10), I’m going to set things up so the Field current goes to 0 when the engine is below 1000rpm. That will make idle and low speed maneuvering (in the marina, retrieving the anchor) much better without the alternator drag.

Another thing is that something like the WS500 will integrate with your Victron system, and let you run DVCC. As your batteries approach fully charged, it will tail off the alternator output as requested by the system. When they go full, it will go into a 0A mode, where it’s adjusting itself to keep its output matched to your house loads, and the battery charge current at 0.

Definitely the optimal way to go, imho.
That’s an interesting option worth exploring. I had concerns about a larger externally regulated alternator borrowing power from my smallish engine. Good to know that it’s possible to set parameters to ensure enough engine power is available to push the boat without too much compromise.
 
That’s an interesting option worth exploring. I had concerns about a larger externally regulated alternator borrowing power from my smallish engine. Good to know that it’s possible to set parameters to ensure enough engine power is available to push the boat without too much compromise.
The other thing you can do (both the Balmar and Wakespeed regulators support this) is rig up a switch that will cut the alternator load in half. If you need that extra couple of HP on the prop, just flip the switch. My co-owner and I have been jokingly referring to it as the magic/more magic switch. (Deep geek reference there).
 
If I was you, I’d take the alternator to an alternator shop and have them modify it for external regulation. It’s a pretty easy modification for them to make. There are significant benefits to having something smarter run your alternator.

Aside from controlling it WRT temperature, you can do things like phase in alternator power above a certain RPM. For small engines like ours (I have a 1GM10), I’m going to set things up so the Field current goes to 0 when the engine is below 1000rpm. That will make idle and low speed maneuvering (in the marina, retrieving the anchor) much better without the alternator drag.

Another thing is that something like the WS500 will integrate with your Victron system, and let you run DVCC. As your batteries approach fully charged, it will tail off the alternator output as requested by the system. When they go full, it will go into a 0A mode, where it’s adjusting itself to keep its output matched to your house loads, and the battery charge current at 0.

Definitely the optimal way to go, imho.
This is the best way to go. But although modifying the alternator is cheap, the WS500 isn't. Worth exploring if you otherwise would be paralleling many DCDC converters to get to near 100A. If you only desire to charge at 30A, then a DCDC is much cheaper.

I will also comment that the WS500 is the regulator to buy. The alternative from Balmar is nearly impossible to setup and program.
 
This is the best way to go. But although modifying the alternator is cheap, the WS500 isn't. Worth exploring if you otherwise would be paralleling many DCDC converters to get to near 100A. If you only desire to charge at 30A, then a DCDC is much cheaper.

I will also comment that the WS500 is the regulator to buy. The alternative from Balmar is nearly impossible to setup and program.
I agree with this. But it really depends how much charging you expect to do with the engine/alternator.

The least expensive option is a good DC to DC charger like the Victron Orion. This is the system I am going to use. I do not expect to use the engine for charging except when I am under power and actually going somewhere. The Orion will prevent the alternator from destruction.

If on the other hand you expect to use the engine for charging regularly the Wakespeed option is the best. Then use a DC to DC charger to keep the start battery charged with the alt output to the lithium bank.

I agree that Balmar programming is terrible - you would think they would have updated it by now.
 
As components are now arriving,
I’m in the process of upgrading the system on my sailboat and a little overwhelmed by the complexity of most of the schematics from Victron. Can’t seem to find one that closely resembles what I’m trying to do.

-1 lead acid start battery

-100 amp internally regulated alternator

-Orion 12-12 30 amp isolated DC-DC charger

-2 206Ah Lithium batteries w/ integrated BMS (these are still stuck on a container ship!)

-1 Multiplus 3000 12v inverter charger

-2 Victron MPPT charge controllers to be added (planning two arrays totally approx. 600 watts)

-Cerbo GX

-Victron Smart shunt (500Amp)

-Both AC and DC

Can someone point me in the right direction in terms of an appropriate schematic?
Thanks in advance!
 
I have a BMV700 with the Bluetooth dongle and I get 100 feet communication with it in a house and also have a Smartshunt and only get like 15 feet....FYI

With the shading on a sail boat I would put individual inverters on each panel to get the most out of the system.

From the research I have done it is most versatile to hook the alternator to the house battery and have a dc to dc to charge the lead acid starter battery though I don't live on a boat but hope to at some point......good luck.
 
Thanks for the feedback. My boat is only 33' long and the system will be placed centrally, so I should be good with the limited range of the Smart shunt.
 
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