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Marine hybrid System

Zoodles

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In order to adhere to my "KISS" approach, which will save money and ultimately be easier to troubleshoot and repair (when we spend our annual 2 month trips to the remote areas of Central and North BC Coast) I have devised a simple and relatively inexpensive circuit to apply Lithiums to my legacy boat system.
So, I will configure the alternator/(Balmar regulator) and the solar MPPT to charge for LifePO4 parameters and the AC shore charger for lead acid. (But I can still use it to give the LifePO’s a ‘boost’, if necessary). With the appropriate switches I can charge or send the load to either bank if necessary...

1648864878805.jpeg

Any red flags or comments??

Thanks in advance.
 
I would consider a dc-dc converter (instead of the isolator) so that your L.A. batteries can charge the lifepo4 while underway, or while being charged by the ac charger.
 
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That's a similar set up to my "legacy" system setup. Also, I too would recommend a dc-dc converter instead of the isolator.
 
I would consider a dc-dc converter (instead of the isolator) so that your L.A. batteries can charge the lifepo4 while underway, or while being charged by the ac charger.
Given that he has an MC-614 regulator which can allow the alternator to charge the LiFePO4, I would do it the other way and have a DC:DC charge the starter battery. That's what I'm doing on my boat.
 
I actually had a cct diagram with a dc-dc chgr, but decided I don't want the converter to discharge my 'start/reserve' battery when the motor is not running and don't see the advantage, since I have 3 separate means of charging under different circumstances... as well as the fact of the charger limiting charge current to 30A or less...
 
I actually had a cct diagram with a dc-dc chgr, but decided I don't want the converter to discharge my 'start/reserve' battery when the motor is not running and don't see the advantage, since I have 3 separate means of charging under different circumstances... as well as the fact of the charger limiting charge current to 30A or less...
In my experience, the Orion TR in float mode is only a few watts when I had it on the bench. I was running a Cerbo GX, the Orion, a BMV-712, Smart Shunt, and Netgear LTE router off a bench top power supply. The whole thing was only drawing about 12W once the Group 24 starting battery was in maintenance mode.

That said, once I get the system on the boat, I'll be turning the Orion on/off under software control depending on my charging sources. (I'll be using Node Red on the Cerbo to open/close the relay on the BMV-712, which in turn will be wired to the input on the Orion).
 
I actually had a cct diagram with a dc-dc chgr, but decided I don't want the converter to discharge my 'start/reserve' battery when the motor is not running and don't see the advantage, since I have 3 separate means of charging under different circumstances... as well as the fact of the charger limiting charge current to 30A or less...
I actually had a cct diagram with a dc-dc chgr, but decided I don't want the converter to discharge my 'start/reserve' battery when the motor is not running and don't see the advantage, since I have 3 separate means of charging under different circumstances... as well as the fact of the charger limiting charge current to 30A or less...
The DC-DC charge converters allow current drain from starting battery? I have the Renogy DC-DC 50amp with MPPT and I don’t get any current draw from the starting battery. That’s by design as far as I can tell.
 
The DC-DC charge converters allow current drain from starting battery? I have the Renogy DC-DC 50amp with MPPT and I don’t get any current draw from the starting battery. That’s by design as far as I can tell.
My Renogy DC-DC chargers have an integrated "Turn On" relay so that they only operate when (in my case) the alternator is operating. This means they are not constantly vampire-drawing from the source battery to the destination battery.

I get an ignition signal from my engine control panel to a shared bus and there I connect the charger relays. I suppose you could use a voltage sensitive relay to turn on your DC DC chargers when your PV panels were operating in excess of a settable voltage, too.

I put a diagram of my system in this thread.
 
I finally finished the installation of the battery build on my sailboat - space was tight but all-in-all quite happy with the results.
My cells arrived well-matched (at 60% level). There was only one cell with a .005 V difference, top balance showed two cells about .05-.07 V higher, the rest were fairly close. Installed the 8 - 280Ah cells in 2P4S config. I use a Lifeline AGM as start/reserve on the other output of the Argofet Isolator.
 

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To avoid damage to the CC, Switch the panel to CC connection before switching the CC to battery connection. I have sucsefully switched both using a DPST switch.
 
Seems there is reluctance to use the capacity of the alternator (50 or 60%) and only use a DC-DC converter instead of the argofet
direct to LiFePO4 bank. What are the reasons for this rationale?
Thanks in advance.
 
Seems there is reluctance to use the capacity of the alternator (50 or 60%) and only use a DC-DC converter instead of the argofet
direct to LiFePO4 bank. What are the reasons for this rationale?
Thanks in advance.
Alternators can easily overheat and burn themselves out. Most alternators are designed to re-charge lead acid starting batteries. This means that they only need to offer a lot of amps for a short period to re-charge a lead acid battery, which can't absorb amps nearly as fast as lithium.

So, if you charge a much-depleted lithium battery, unless you are managing the output of the alternator, you can easily overheat the alternator, cause a fire, cause it to burn out, etc..


If you throttle the alternator to a fraction of the rated production, you are less likely to experience overheat.

DC DC chargers help to specify the amps and volts that you feed into the battery being charged. If you put lots of amps into your lithium battery each time you charge it (vs. charging gradually at lower amps) you risk lessening the life span of your battery.

Your mileage may vary.
 
My alternator is a 115A Bosch I modified to external regulation with a Balmar mc614. It has forced external air and for current FLA,s doesnt need field reduction. With the LFP install I will throttle back to whatever keeps it cool ~70A.
I will still use it this way direct to house LFP bank and either dc dc to start or use the argofet.
I’m aware LFP profile is not ideal for start SLA battery and a smart dc dc would be more configurable but I already have the argofet.
I’m surmising that is the reason ppl shy away from argofet. That, and a supposed possible flaw in argofet fault mode.https://community.victronenergy.com/questions/59171/argofet-200-2-energize-passing-current-to-output.html

Kept <90A, no problem with v belt setup and belt dust so you that is not a factor.
Sorry this is a major thread drift, which needs a thread of its own so I will discontinue.
 
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Your Bosch 115A sounds good. Alt Temp monitoring is essential and the Balmar mc614 has that, it also has belt manager settings which limit field output. These are good strategies for preserving alternators and not over taxing them. However you need to consider one additional thing which is sudden shutdown of the LFP BMS which can cause a voltage spike that will fry your alternators diodes. DC-DC chargers are a good strategy or having a Wakespeed WS500 linked to a communicating BMS with relays on the charge bus. This is not a setup for drop in LFP.

Are you going to try to manage the charging between your 560ah AGM and the 800ah LFP without using a BMS, but using a switch or something?

I see you have the alternator setup using LFP paramters, which I think is good, and if you charge the LFP with a DC-DC converter, that should help protect the Alternator from LFP BMS cutoff spikes.

Later: That all looks very neat. The boxes look good, did you make them? What material? I see you did use an argofet.
 
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I currently have the argofet for load dump to start battery if bms disconnects.
Also a victron BMV712 set to lower than bms cutoff that switches power to ext regulator via relay.
Plus alternator protection module, so I think I'm covered.
Not enamored by argofet tho, as its not smart to cover engine SLA batteries needs as LFP setting will not be ideal.
I'm thinking of swapping to Orion TR smart DC /DC (isolated)
 
Your LFP bank is huge and allows flexibility.

I have a engine start 12vdc gel-cell 70A from west marine that is about 14 years old, I think it has lost about 20%-30% of its capacity, but I keep it charged up all winter about once a month, and then while it is on the boat it doesn't get charged until I put my battery switch on both to use the house bank to partly recharge the start because I don't want the alternator/regulator to overcharge it at 14.8v (for the Trojan T-105 House Bank) . I do that once or twice a summer. The start battery seems to survive this abuse pretty well and still starts the engine. Starting our engine doesn't take much power, particularly in the summer, so maybe a DC-DC isn't really worth it, maybe just a small Solar Panel? However in an ideal setup, I think the starter battery should be used as backup for essential sailing systems, in case the BMS/LFP fails. I think you have that capability.
 
When I look at your Final Diagram which does allow switching the DC Panel to LFP or FLA, I wonder how your BMS disconnects the LFP and where the switch/relay or battery isolator is located?
 
When I look at your Final Diagram which does allow switching the DC Panel to LFP or FLA, I wonder how your BMS disconnects the LFP and where the switch/relay or battery isolator is located?
The BMS disconnects the negative lead between the LFP and shunt, the FLA stays in circuit to handle the load dump. The Argofet IS the isolator...
 
Thanks Zoodles, I see, the BMS is where the disconnect occurs.
What are your thoughts about charging the FLA at LFP rates? Do you think it is an insignificant problem? For example a FLA might require 14.6v - 14.8v according to the manufacturer, and a long acceptance, but a Gel-cell doesn't want more than 14.1v but also requires an acceptance period. Maybe it is most practical to get a good but inexpensive LFP and just use it as long as possible and not worry... Is this one reason you have the 1,2,both switch, so you could put it on "both" and have the solar and LFP charge the start battery up?
 
Alternators can easily overheat and burn themselves out. Most alternators are designed to re-charge lead acid starting batteries. This means that they only need to offer a lot of amps for a short period to re-charge a lead acid battery, which can't absorb amps nearly as fast as lithium.

So, if you charge a much-depleted lithium battery, unless you are managing the output of the alternator, you can easily overheat the alternator, cause a fire, cause it to burn out, etc..


If you throttle the alternator to a fraction of the rated production, you are less likely to experience overheat.

DC DC chargers help to specify the amps and volts that you feed into the battery being charged. If you put lots of amps into your lithium battery each time you charge it (vs. charging gradually at lower amps) you risk lessening the life span of your battery.

Your mileage may vary.
If you use an intelligent regulator (either Balmar or Wakespeed) it will measure the alternator temperature and throttle back the field current to keep the alternator below said temperature. This lets it ride as high as it can, without burning out your alternator.
 
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