Weebles - 8-wks to lift-off (Baja Ha Ha)

[mvweebles]

Fingers crossed, getting closer to turning the page from '/plan/dream/prep' to actual departure with the Baja Ha Ha fleet around Halloween. Still much to be done.

I put-on 250 gals of diesel the other day to add to the 80 that was aboard. I probably have room for another 100 but do not want the weight. Boat is already stern-low.

Trim-ballast. Now that the boat is roughly loaded, I need to have ballast moved. I had about 300# of lead ingots placed beneath starboard side deck. Most of that needs to be moved to forward center/bilge area to even-out a stbd list, and hopefully pull the bow down a bit. I'll go to the yard on Tuesday for this as they have a young skinny kid who fits into the side-deck access area.

Alternator/Charging. Right now, my biggest single concern. I have over-complicated this system and I may unwind it - asking for feedback please. My house bank is 700AH of LFP (LiFePO4). I had a 75A Balmar and added a 120A Balmar so I have two alternators on the engine controlled by a Balmar 612-DUAL regulator (it's made for exactly this type of application). Right now, not getting much amperage charge out of it. First step is to make sure the programming is correct, but it may be there was a mistake in wiring. There are a LOT of control wires between the Regulator and the Alternators.

I was talking to a good friend who is very knowledgeable about this type of stuff, though not so much about LFP. He asked a good question (which I pose - amended - to the TF Bigger Brain): "Pete, why don't you just install Leece Neville large frame with internal regulation and be done with it?"

QUESTION: why not just go with a somewhat old-school internally regulated 'coach' Leece Neville alternator rated for continuous duty? One of the big benefits of external regulators is they give a stepped-charge, but LFP seem to like a constant (or near constant) charge. The other function of a regulator is it keeps the alternator from going over-current, but what I don't know is would a 160A alternator produce more than 160A; and is that okay for an alternator rated at 160A continuous? I'll call Prestolite on Monday, but thought I would pose the question.

My wife flies into San Diego next Wednesday. We'll take the boat to San Diego a few days after to visit some friends and get additional hours on her. Honestly, I am surprised how nervous I am about driving the boat. I've had her for 25-yrs but so much is new, so much to still calibrate and learn. I have a certain triage mentality - some stuff needs to be done here while I have access to the boatyard, though I confess, much of the work is well within my capabilities but I just don't have the hardcore desire.

Will haul Weebles on Sept 20th with a punch list of items that will take about 2-weeks of work. During this time, my wife and I will drive our car back to Colorado where she normally lives in the cellar of our cabin. We'll rent a car one-way and drive back San Diego for the final push.

Peter

 

[O C Diver]

Yes you made it overly complicated. 2 alternators for 2 separate battery banks. Add a paralleling switch for emergencies and call it good.

To answer your question, my 220 amp Leece Neville alternator will bench put out 250 amps. However, you have to spin it at full RPM. Most installations aren't doing over 75% RPM.

Ted

 

[mvweebles]

Ted - very interested in your feedback. To clarify, the two alternators act as one with the Balmar regulator. Charge to house 700ah LFP bank with DC-DC charge to engine and generator AGMs. I do have a parallel switch.

What is your house bank? LFP or AGM/FLA? I guess the core of my question is for a large frame alternator rated for continuous duty, does it really need advanced regulation for LFP? BTW - I very, very rarely run WOT.

Thanks for feedback

Peter

 

[ksanders]

Peter

We are planning on leaving Ensdenada sometime shortly after the 15th of October and heading home to La Paz, weather permitting

We do not have an exact date except that we need to be in La Paz on the 8th of November so we need to make the trip down the coast either before or after that date.

It sounds like you are on roughly the same schedule.

 

[Delfin]

Fingers crossed, getting closer to turning the page from '/plan/dream/prep' to actual departure with the Baja Ha Ha fleet around Halloween. Still much to be done.

I put-on 250 gals of diesel the other day to add to the 80 that was aboard. I probably have room for another 100 but do not want the weight. Boat is already stern-low.

Trim-ballast. Now that the boat is roughly loaded, I need to have ballast moved. I had about 300# of lead ingots placed beneath starboard side deck. Most of that needs to be moved to forward center/bilge area to even-out a stbd list, and hopefully pull the bow down a bit. I'll go to the yard on Tuesday for this as they have a young skinny kid who fits into the side-deck access area.

Alternator/Charging. Right now, my biggest single concern. I have over-complicated this system and I may unwind it - asking for feedback please. My house bank is 700AH of LFP (LiFePO4). I had a 75A Balmar and added a 120A Balmar so I have two alternators on the engine controlled by a Balmar 612-DUAL regulator (it's made for exactly this type of application). Right now, not getting much amperage charge out of it. First step is to make sure the programming is correct, but it may be there was a mistake in wiring. There are a LOT of control wires between the Regulator and the Alternators.

I was talking to a good friend who is very knowledgeable about this type of stuff, though not so much about LFP. He asked a good question (which I pose - amended - to the TF Bigger Brain): "Pete, why don't you just install Leece Neville large frame with internal regulation and be done with it?"

QUESTION: why not just go with a somewhat old-school internally regulated 'coach' Leece Neville alternator rated for continuous duty? One of the big benefits of external regulators is they give a stepped-charge, but LFP seem to like a constant (or near constant) charge. The other function of a regulator is it keeps the alternator from going over-current, but what I don't know is would a 160A alternator produce more than 160A; and is that okay for an alternator rated at 160A continuous? I'll call Prestolite on Monday, but thought I would pose the question.

My wife flies into San Diego next Wednesday. We'll take the boat to San Diego a few days after to visit some friends and get additional hours on her. Honestly, I am surprised how nervous I am about driving the boat. I've had her for 25-yrs but so much is new, so much to still calibrate and learn. I have a certain triage mentality - some stuff needs to be done here while I have access to the boatyard, though I confess, much of the work is well within my capabilities but I just don't have the hardcore desire.

Will haul Weebles on Sept 20th with a punch list of items that will take about 2-weeks of work. During this time, my wife and I will drive our car back to Colorado where she normally lives in the cellar of our cabin. We'll rent a car one-way and drive back San Diego for the final push.

Peter

Peter, you'll get differing opinions on LFP, but mine seem to be going strong after 5 years with zero reduction in capacity, so FWIW...


LFP do not like a constant charge. If you keep pumping current to them after full you'll destroy them. My charge cycle (24v) is to charge them at 33% capacity with "Bulk" voltage set to 29.2 vdc, which is the voltage level that when reached triggers balancing of the cells courtesy of the BMS. "Absorption" phase is held for only a couple of minutes - 15 at most - then I either stop charging them and start using them, or I take them off line and run under power or at the dock with charge current going to the LA starter bank. In other words, I use the LFP bank like a fuel tank - use it, fill it, stop filling it, use it, repeat.... Incidentally, I use a rotary switch and the shut off on the BMS to take the LFP off line when I'm done charging but underway and bring the LA starter bank online. So I never "Float" the LFP bank, although many do, but if they do, it is critical that the float voltage on the regulator be set very low. Since I never float mine, I don't know what that voltage would be, but I believe it is a function of how much current is being drawn from the LFP bank when it is being floated.



Using an internally regulated alternator would be a very bad idea for LFP, so please don't. That said, the Balmar can't be set up correctly, or you are trying to charge an LFP bank that is already full. If the bank hits 14.4 to 14.6 vdc, it is definitely full. If the LFP are sitting at 13.1, they are somewhere between 25% and 80% charged, but will accept the higher current and are full when the absorption rate drops to about 5% of capacity. Which brings me to the importance of some means of measuring voltage and current flow into and out of the LFP bank. I use a Link 20 but Victron and others make monitors you need if you don't have one. Simply put, you need to know how much juice you've taken out of the LFP so you know how long they need to be charged.


You didn't mention that you have a BMS, or is it internal to the battery?


Operationally, and assuming you have an LA starter bank, your run to the Sea of Cortez will be made underway with the LFP bank offline until you get to an anchorage, then you could start using the LFP.


Sorry for the ramble, but I hope that helps.

 

[mvweebles]

Peter

We are planning on leaving Ensdenada sometime shortly after the 15th of October and heading home to La Paz, weather permitting

We do not have an exact date except that we need to be in La Paz on the 8th of November so we need to make the trip down the coast either before or after that date.

It sounds like you are on roughly the same schedule.

We decided to join the Baja Ha Ha fleet - this may be their last year. In the past, the fleet did not check-in to Mexico until they arrived in Cabo. The Mexican Govt has decided the fleet much check in at their first landfall which adds some complexity to the logistics (doesnt apply to us as we'd depart from Ensenada). And after 30+ years, I guess it's time to call it a day.

Personally, I don't think I'd join the Ha Ha, but I really want the beginning of our cruise to be as comfortable as possible for my wife. It's been a long time, and she's worried about overnight runs - she has a bit of a negative memory from a trip we did to the Channel Islands many years ago. I guess my delivery mentality didn't blend well. I'm hopefully older and wiser now. So we'll have a third crew for the run south which worked well on our run from San Francisco to Ensenada (500hms).

Our plans are truly open-ended. Current thinking is to bypass Cabo and even La Paz and head to Mazatlan.

I think there are a couple other TF'ers making the trek south. Perhaps another thread is in order for just the run......

Peter

 

[mvweebles]

Peter, you'll get differing opinions on LFP, but mine seem to be going strong after 5 years with zero reduction in capacity, so FWIW...


LFP do not like a constant charge. If you keep pumping current to them after full you'll destroy them. My charge cycle (24v) is to charge them at 33% capacity with "Bulk" voltage set to 29.2 vdc, which is the voltage level that when reached triggers balancing of the cells courtesy of the BMS. "Absorption" phase is held for only a couple of minutes - 15 at most - then I either stop charging them and start using them, or I take them off line and run under power or at the dock with charge current going to the LA starter bank. In other words, I use the LFP bank like a fuel tank - use it, fill it, stop filling it, use it, repeat.... Incidentally, I use a rotary switch and the shut off on the BMS to take the LFP off line when I'm done charging but underway and bring the LA starter bank online. So I never "Float" the LFP bank, although many do, but if they do, it is critical that the float voltage on the regulator be set very low. Since I never float mine, I don't know what that voltage would be, but I believe it is a function of how much current is being drawn from the LFP bank when it is being floated.



Using an internally regulated alternator would be a very bad idea for LFP, so please don't. That said, the Balmar can't be set up correctly, or you are trying to charge an LFP bank that is already full. If the bank hits 14.4 to 14.6 vdc, it is definitely full. If the LFP are sitting at 13.1, they are somewhere between 25% and 80% charged, but will accept the higher current and are full when the absorption rate drops to about 5% of capacity. Which brings me to the importance of some means of measuring voltage and current flow into and out of the LFP bank. I use a Link 20 but Victron and others make monitors you need if you don't have one. Simply put, you need to know how much juice you've taken out of the LFP so you know how long they need to be charged.


You didn't mention that you have a BMS, or is it internal to the battery?


Operationally, and assuming you have an LA starter bank, your run to the Sea of Cortez will be made underway with the LFP bank offline until you get to an anchorage, then you could start using the LFP.


Sorry for the ramble, but I hope that helps.

Thanks Delfin - not a ramble, and definitely helps. I do have full Victron monitoring (Cerbo).

My LFP's are Lion Energy Safari. For some reason, Victron has a special set of instructions for them to setup at 13.9v Absorption; 13.9v Float. Which is why I thought a constant voltage alternator would make sense. I see this is not common - PKYS recommendations for setting the Balmar is Bulk = 14.3v; Absorption = 13.6v; Float = 13.4v. No idea why the Lions are constant voltage for charging - they are prismatic cells.

But I am way over my skis here so input is appreciated. Sounds like I need to talk to Lion Energy too - in the past, their tech support has been okay.

Thoughts?

Peter

 

[twistedtree]

I think with LFP you are best off with a smart regulator of some sort. You only need two stages, bulk and float, but it's good to have two. If you have a fixed voltage regulator, it needs to reliably operate below the full charge voltage of your LFP bank. Otherwise you risk BMS disconnects while underway, which you really don't want.


When you say the alternators are producing too much current, what sort of numbers are we talking about? Ted's experience is the first I have heard of an alternator producing more than rated current. I just want to confirm there isn't something else going on that should be addressed.


As for large frame, continuous duty alternators, I'm not sure that such a thing exists. Some are better than others, no doubt, but I have a pair of such alternators on my main engine and my regulator has to throttle them back to keep temps acceptable. I don't think they would catch fire and burn like smaller alternators, but they will rise to well over 300F which will shorten their life. Mine end up running at about 80% of rated output once heat soaked. I still think they are the best option, but they aren't perfect.


Another consideration is that in your application you have two alternators on the same engine, but charging the same battery bank. In that case you don't need a dual. A single regulator will work. You just wire the regulator field output to both alternator field inputs, and it drives both in parallel. At any given time, each alternator will output the same percentage of it's full output capacity. So if the regulator is calling for 50% output, the 75A alternator will put out 37A, and the 120A alternator will put out 60A. They always work together, each producing according to it's capabilities. That would simplify your wiring a bit, but since you already have the dual, probably isn't worth it. One consideration with a single regulator like I describe is that there is only one temp sensor, so you need to pick which alternator to put it on. I think the best approach is to pick one, then check alternator temps when running with max sustained load to see how much difference there is between the alternators. If you don't already have the temp sensor on the hottest, move it.


But first, let's talk more about what's not working as expected. Hopefully there is a simple fix because there is nothing fundamentally wrong or misguided with what you have.

 

[Bmarler]

The 612 dual should be programmable for lfp, but I haven’t gone through the parameter list on it.
I pulled my 612 and changed to the new 618 since I have the balmar smart shunt in place. I love this setup as I can pull the advanced parameter list up on my phone and make adjustments in real time.
If you changed to this regulator you’d probably need to do both and add a centerfielder. Probably more than you want to do.
On a cruising boat I’d never go back to internal regulation. External shortens the charge time dramatically, and is better for the batteries health.

 

[Delfin]

Thanks Delfin - not a ramble, and definitely helps. I do have full Victron monitoring (Cerbo).

My LFP's are Lion Energy Safari. For some reason, Victron has a special set of instructions for them to setup at 13.9v Absorption; 13.9v Float. Which is why I thought a constant voltage alternator would make sense. I see this is not common - PKYS recommendations for setting the Balmar is Bulk = 14.3v; Absorption = 13.6v; Float = 13.4v. No idea why the Lions are constant voltage for charging - they are prismatic cells.

But I am way over my skis here so input is appreciated. Sounds like I need to talk to Lion Energy too - in the past, their tech support has been okay.

Thoughts?

Peter

View attachment 141727

Sounds like Victron may have a typo in their instructions? When you talk to Lion, ask them if their BMS allows for cell balancing, and if so, at what voltage does it kick in. That is a voltage you'll want to bring the bank to occasionally, or almost every time, which is what I doing 80% of the time.


PKYS's recommendation might be fine, or if cell balancing occurs at 14.4 volts, not so fine.


In the chart you posted, it shows 'Absorption volts' of 13.6. As I recall, the Balmar only allows a time parameter for absorption, not a voltage different from bulk. But maybe I'm misremembering, but if not, the time at peak voltage should be very, very short....


FYI, but TT is an expert in all this....

 

[Bmarler]

Some balmar required a different volt setting at absorption than bulk. (I thought)
There should be a time at volts till amps drop off to trigger float.

 

[Bmarler]

I just re-read the chart. I don’t have lithium so I’m not up to speed on the volt settings, but it’s interesting that the bulk and absorption voltages are that far apart. I thought the main thing that differed bulk from absorb is that bulk is for trying to get the battery voltage up and pumping as much current as possible till you get there. Once at voltage, you switch to absorb. Maintain voltage and taper current till you get to a low current output and then trigger float.
Essentially, two volt settings.
Lithium must be handled differently, but those volt settings in the chart don’t really make sense to me.

 

[ksanders]

I just re-read the chart. I don’t have lithium so I’m not up to speed on the volt settings, but it’s interesting that the bulk and absorption voltages are that far apart. I thought the main thing that differed bulk from absorb is that bulk is for trying to get the battery voltage up and pumping as much current as possible till you get there. Once at voltage, you switch to absorb. Maintain voltage and taper current till you get to a low current output and then trigger float.
Essentially, two volt settings.
Lithium must be handled differently, but those volt settings in the chart don’t really make sense to me.

Agreed...

I have FLA and it's simple...

The charger goes to full output until the batteries reach 14.36 volts. (bulk)

Then the charger holds that voltage and limits current to do so (absorbtion)

Then the charger reduces the voltage to the float voltage with the trigger to do so being either time or low current.

 

[mvweebles]

Thanks so much Gents. I will spend some quality time learning to program the Balmar - my strong hunch is the installer did not program it. Frankly, the little magnet-thingy and cryptic code display looks like a recipe for total frustration. I would think that in 2023, with Apple having over 150k employees, every company with a GUI would have hired an Apple person to make their interface usable without significant learning curve.

I also sent an email to Lion Energy batteries. I searched my email and found a response from 2-years ago that just said "charge at 13.9." That was their entire response. Call me cynical, but didn't instill confidence back then, even less now.

Here's what I sent - fingers crossed I get something more usable:

What are the charge settings for Victron MPPT, BMV; and Balmar Smart Regulator? I am really confused.

1. There is a document (ATTACHED) on Victron's site that states for Lion, 13.9v Bulk/13.9v Absorb. This is much different than other LFP batteries.
2. The FAQ on the Lion Energy site (HERE) states up to 14.6v, but at least 13.9v
3. For all other types of LFP batteries, recommendation is 2-stage charge: 14.3 Bulk; 13.6 Absorb (at least for the Balmar Regulator - ATTACHED)

.
So what do you recommend????? There is significant variance in the above. My understanding is LFP batteries require some special care for charging - please advise. ​

 

[twistedtree]

Some balmar required a different volt setting at absorption than bulk. (I thought)

There should be a time at volts till amps drop off to trigger float.

I’m not sure if it changed in the latest model, but historically the Balmar’s have a separate absorb voltage, and it has to be at least one notch lower than Bulk, where a “notch” is whatever increment they allow - probably 0.1V

 

[Bmarler]

It seems to have changed with the 618.I have my bulk and absorption set the same.
With the new interface via Bluetooth the advanced parameters are so easy to set, no hanging out by the engine with the screwdriver magnet.
Plus, there are additional parameters that were not available before.
For me, it was an easy decision to upgrade to the new one. Still keeping the old 612 for a spare.

 

[Comodave]

On our last boat I put a Balmar regulator in. I bought the 10’ extension harness and actually put the regulator in a cabinet in the salon so I could sit comfortably while I programmed it. The magnetic screwdriver deal was kinda a PITA.

 

[guy with a boat]

The differences in recommended charging voltage between LFP manufacturers is often due to BMS specifics, rather than any differences in resulting cell voltage. Battleborn, for example, calls for an “absorb” period at 14.4v/28.8v. This is how they achieve cell balancing with their built-in BMS, and the voltage of the fully charged batts are whatever other LFP batts are (27.8 or so for our 24v system). I’m not familiar with the batts you have so I don’t know if this applies.

Floating an LFP bank is ideally just allowing the altnerators to carry the house loads, and is usually done at some lower voltage that isn’t 100% SOC. This is actually its own topic and TT has some great thoughts on this (LFP float) that he’s shared in previous threads.

I would never use an internal regulator with LFPs, and unlikely with AGM if I had a choice. The Balmar regulator is a bit of a pain to program, but the capabilities are worth it. BTW, I’ve run 2 alternators to house bank with one Balmar and with 2, and either setup works. TT explained the way they work together despite different sized alts.

Don’t run even a big alternator into an LFP bank without throttling it through your Balmar regulators. I smoked a 190amp/24v Balmar by feeding an LFP bank unthrottled. The Balmar is just a slightly upgraded large-frame Leece Nevile/Prestolite with a paint job. Now I run two large alternators throttled at 84% through the regulator settings and they run all day without overheating.

Glad to hear that you will be out cruising soon. Try to make all your changes/fixes before your shake-down trip so you can work out the kinks before departure and enjoy your trip.

 

[O C Diver]

Ted - very interested in your feedback. To clarify, the two alternators act as one with the Balmar regulator. Charge to house 700ah LFP bank with DC-DC charge to engine and generator AGMs. I do have a parallel switch.

What is your house bank? LFP or AGM/FLA? I guess the core of my question is for a large frame alternator rated for continuous duty, does it really need advanced regulation for LFP? BTW - I very, very rarely run WOT.

Thanks for feedback

Peter

Seems like a lot of unnecessary complexity. Have the standard alternator charge the start battery for the engine. Put nothing else on the engine battery, so you will know you can always start the engine. Have your second alternator charge the house bank with an external regulator that will charge your LiFepo4 batteries. If you need a bigger second alternator, buy it. The Center Fielder and DC to DC charger are adding levels of complexity that become failure points.

I have AGM Firefly batteries and use a Balmar MC - 614 regulator. The system is simple and just works. Doubt I will own the boat next time the house bank needs to be replaced.

From memory 9 years ago when I bought the Leece Neville alternator, the service technician who bench tested my alternator said that Leece Neville intentionally understated their output at maximum RPM so that there were never issues with reaching name plate amperage. For what they were designed to do, an extra 10% capacity wasn't going to hurt anything with their standard regulator. Will have close to 6,000 hours on the Leece Neville alternator at the end of the year, with zero maintenance! Will probably show it some love and replace the bearings and brushes.

Ted

 

[Comodave]

That is sorta the way I was setting up our last boat. It had twins so the port engine was going to charge both start batteries. The starboard engine was going to charge the Lithium house batteries with a smart regulator. I sold the boat before I got the large alternator installed on the starboard engine. The start batteries had an ACR connecting them for charging.

 

[Simi 60]

Late in here but I found the specs on the Balmar alt to be shite for our application on a slow spinning engine, they put out bugger all amps at low rpm.
Glad I found out here before pulling the trigger on it.

Instead I got a pair of 2nd hand but unused genuine Delco Remy 24v 100amp alts (1 in use and a spare) and they actually put out 100amps @ our 1150rpm cruise.

Decided on sterling 35amp dc2dc X2 from lead starts to Lifepo4 house which effectively derated the alt to 70% and the temp so far, has stayed below 67c

Relatively cheap and easy result for us compared to Balmar/Wakespeed.
Sterling charger has a lifepo4 charging profile with shutdown
Don't need additional charging source for starts
Don't have to worry about BMS shutdown load dump killing alts

 

[mvweebles]

On a separate sub-topic, I emailed Lion Energy (LFP OEM) querrying about their recommended 13.9V Absorb/13.9V Float recommendation (every other LFP battery has at least a 0.2V difference).

Their response was only slightly longer than "The settings work great! We recommend them!"

So I responded and (respectfully) asked why their reccommendation was significantly different - what was different about their batteries; and why does their FAQ documentation state the batteries can be charged up to 14.6v? Their response was "Some users have tried 14.6v with Victron and they've gotten an alarm. 13.9v is the lowest fully-charged voltage so we recommend that."

Is it just me, or does that response seem like empty calories? A response without an explanation - no indication of what the alarm was, or any diagnostics on what might be causing it, just dial-back to the minimum.

I'm tempted to run 14.2v/13.9v - any feedback?

Peter

 

[Ka_sea_ta]

After reading all the responses to this I think you are making it overly complicated and leaving a single point failure ( a BMS disconnect) If I was doing this I would do as Ted suggested with one alt for the house and one for starting. Use your DC 2 DC from starting to help with charging the house. A would also add the Balmar APD to the house alternator ( I have this concern of BMS disconnects ) This configuration would allow to optimize the charging profiles for both types of batteries. Good luck

 

[Simi 60]

( I have this concern of BMS disconnects )

If your charger has been setup properly, it will disconnect before BMS.

BMS should be the VERY LAST line of defence IMHO

 

[mvweebles]

After reading all the responses to this I think you are making it overly complicated and leaving a single point failure ( a BMS disconnect) If I was doing this I would do as Ted suggested with one alt for the house and one for starting. Use your DC 2 DC from starting to help with charging the house. A would also add the Balmar APD to the house alternator ( I have this concern of BMS disconnects ) This configuration would allow to optimize the charging profiles for both types of batteries. Good luck

I have an APM on each alternator. On these batteries, as long as the BMS isn't fried, resetting the BMS is pretty simple.

I have been going back and forth on this all day. I have a 150A and a 75A Balmar, total of 225A. There are advantages to combining them. If I want to deliver 150A to my house bank, the two alternators run at 66% each. If they were split, the larger one would run at 100%, the other 0%. Twice the number of fans to keep them cool too.

In a way, there is more redundency, not less. If one alternator fails, the other keeps going albeit reduced capacity. That said, the regulator is indeed single-threaded so there is a potential vulnerability. Mind you, I have three additional sources of charging: Solar, which pumps-out up to 50a in full sun; small alternator off the generator; and inverter/charger off the generator. It might take me a half-day to charge batteries, but there are several work-arounds if I lose engine generation (if I recall correctly, Simi60 has gone without engine-alternator for a while).

At any rate, I'm working through the gremlins. It's frustrating and I'm out of practice; and the stuff is more complicated. In a way, I long for the day when I had OC Divers setup. But I sure love the potential of LFP and a healthy amount of solar. Absolute game changer.

Peter

 

[Ka_sea_ta]

If your charger has been setup properly, it will disconnect before BMS.

BMS should be the VERY LAST line of defence IMHO

You have a much higher trust of electronics in a salt water environment then I

 

[Simi 60]

You have a much higher trust of electronics in a salt water environment then I

Is your BMS not electronic?

Like I said, BMS is last line of defence
Implication being that I have other layers of defence before relying on it

 

[O C Diver]

In a way, there is more redundency, not less. If one alternator fails, the other keeps going albeit reduced capacity. That said, the regulator is indeed single-threaded so there is a potential vulnerability. Mind you, I have three additional sources of charging: Solar, which pumps-out up to 50a in full sun; small alternator off the generator; and inverter/charger off the generator. It might take me a half-day to charge batteries, but there are several work-arounds if I lose engine generation (if I recall correctly, Simi60 has gone without engine-alternator for a while).

Peter

Peter, you get your redundancy with my system by using the paralleling switch. If the second alternator fails you parallel the banks while cruising and separate them when engine off. It may not be the perfect profile, but should suffice until you can replace the alternator.

Ted

 

[twistedtree]

I think a lot comes down to how much alternator power you want while underway. Are you just charging house batteries, and if so, how quickly do you want to recharge them? Or do you have other larger underway loads that you'd like to run off alternators? The more power you want while underway, the more attractive it is to direct all alternator output to the house bank.


Just to get a sense of where this is going on more and more boats, I know of many (including my own) that have dual 200A 24V alternators capable of producing about 10kw while underway. That will charge batteries, run a full size oven, run a full size washer and dryer, run a water maker, and run HVAC. Not all at the same time, but pick any two. These would all otherwise require running a generator.

 

[Simi 60]

But reality is, or at least it is for us, is that the batteries and inverter alone can run these things , not all at once, while not using a generator

Our worst offender is the 2.4kw hot water system, pulls 100amps at 24v but only for 15 minutes
Or air fryer oven, similar pull but maybe 20 minutes