LiFePO4 reference diagram, Alternator version

[s/v Jedi]

Originally Posted by chowdan

That explains a lot on how your drawing is designed. I have a cerbo GX and the BMV, so the cerbo could easily control that relay.

As for the wiring process running the main engine alt to the start and the gen alt to the house, i am not a huge fan of this as that'd mean the alternator really isn't doing much to help my house charge up while motoring. Winter time in PNW doesn't produce solar for us and we sometimes motor or motorsail for 2-3 hours to fight currents and what not, and it'd be ideal to be able to capture the energy from the alternator without having a bunch of DC/DC chargers.

I know i posted a moment ago(before seeing this message), but what about running both alternators to an argofet like discussed, but running the balmar charge profile for LFP and running relay's like you mentioned, but utilizing the small dc-dc victron charger. I think its a 9amp charger. This would mean we'd be focusing 100% on the LFP and relying on the DC-DC charger to maintain/handle the proper charging of the starter and provide all the extra benefits including the cutoff that having the rely in place has.

EDIT:
Reviewing your drawing, i think my proposal of running the primary & dc gen to an argofet with a DC/DC charger from house to start would be completely fine. The FET sole purpose would be functioning as an alternator protector in this instance it appears, but would effectively be how your drawing is except the ALT's run to the FET which runs to LFP/Start.

Might be a waste of an additional $120 as it's not entirely needed, but it sure would be a piece of mind thing though.

In case you want all alternator output to the house batteries:

- two alternators in parallel straight (fuse near battery) into the house batteries, no ArgoFET and both regulators on LFP settings. Remove battery temperature sensors.

- one small dc-dc charger to charge the start battery with correct algorithm. Should almost always be in float when switched on.

- relay with NC contact in the ignition line brown wire of both regulators

- coil of relay in circuit with manual switch and contacts from Cerbo or BMV for automatic on/off. I think programming it to switch regulators off at 90% is a great test. If that works, move it to 95%. I wouldn’t go higher than that.

Note that when you get to 95% the charge current is already reduced and you could simply use a dc-dc converter to finish charge it to 100% if solar isn’t an option. Most of my diagrams are solar oriented because I’m always in or near the tropics.

[CaptainRivet]

Originally Posted by chowdan

That explains a lot on how your drawing is designed. I have a cerbo GX and the BMV, so the cerbo could easily control that relay.

As for the wiring process running the main engine alt to the start and the gen alt to the house, i am not a huge fan of this as that'd mean the alternator really isn't doing much to help my house charge up while motoring. Winter time in PNW doesn't produce solar for us and we sometimes motor or motorsail for 2-3 hours to fight currents and what not, and it'd be ideal to be able to capture the energy from the alternator without having a bunch of DC/DC chargers.

I know i posted a moment ago(before seeing this message), but what about running both alternators to an argofet like discussed, but running the balmar charge profile for LFP and running relay's like you mentioned, but utilizing the small dc-dc victron charger. I think its a 9amp charger. This would mean we'd be focusing 100% on the LFP and relying on the DC-DC charger to maintain/handle the proper charging of the starter and provide all the extra benefits including the cutoff that having the rely in place has.

EDIT:
Reviewing your drawing, i think my proposal of running the primary & dc gen to an argofet with a DC/DC charger from house to start would be completely fine. The FET sole purpose would be functioning as an alternator protector in this instance it appears, but would effectively be how your drawing is except the ALT's run to the FET which runs to LFP/Start.

Might be a waste of an additional $120 as it's not entirely needed, but it sure would be a piece of mind thing though.

Jedi's strategy/philosophy in nearly all his diagrams is to only have the alternator function savely with lifepo4 delivering a fraction of what it could actually do and have solar do the maximum. His diagrams are really good except the alternator solution and that's philosophy should be standing in thick bolt printed red letters underneath in this diagrams.
I strongly disagree with this strategy/philosophy as its a) waiting resources, b) wasting money an c) reduces safety as the alternator is not a real backup anymore and d)often complicate things that introduce additional failure points.

My philosophy is always try to get safely max out of the existing alternator as simple as possible and as cost efficient as possible independent if it's the main charge source or 3rd backup. If the engine runs their is no reason to waste charge from the alternator as long as the battery is not full. A simple switch in the sense wire to shut it off to free spinning when full engine power is needed on a small engine is in 95% cases sufficent.
Eg. DC2DC charger as well as a Wakespeed regulator have their clear purpose where it really makes sense to use them but both are often misused or used when a much simpler and/or economical solution could be used that delivers more output for the same money and/or is saver due to simpler with less failure points.

[newhaul]

Originally Posted by CaptainRivet

Jedi's strategy/philosophy in nearly all his diagrams is to only have the alternator function savely with lifepo4 delivering a fraction of what it could actually do and have solar do the maximum. His diagrams are really good except the alternator solution and that's philosophy should be standing in thick bolt printed red letters underneath in this diagrams.
I strongly disagree with this strategy/philosophy as its a) waiting resources, b) wasting money an c) reduces safety as the alternator is not a real backup anymore and d)often complicate things that introduce additional failure points.

My philosophy is always try to get safely max out of the existing alternator as simple as possible and as cost efficient as possible independent if it's the main charge source or 3rd backup. If the engine runs their is no reason to waste charge from the alternator as long as the battery is not full. A simple switch in the sense wire to shut it off to free spinning when full engine power is needed on a small engine is in 95% cases sufficent.
Eg. DC2DC charger as well as a Wakespeed regulator have their clear purpose where it really makes sense to use them but both are often misused or used when a much simpler and/or economical solution could be used that delivers more output for the same money and/or is saver due to simpler with less failure points.

Post your own diagrams please would like to see how you have your system setup .

[CaptainRivet]

Originally Posted by s/v Jedi

In case you want all alternator output to the house batteries:

- two alternators in parallel straight (fuse near battery) into the house batteries, no ArgoFET and both regulators on LFP settings. Remove battery temperature sensors.

- one small dc-dc charger to charge the start battery with correct algorithm. Should almost always be in float when switched on.

- relay with NC contact in the ignition line brown wire of both regulators

- coil of relay in circuit with manual switch and contacts from Cerbo or BMV for automatic on/off. I think programming it to switch regulators off at 90% is a great test. If that works, move it to 95%. I wouldn’t go higher than that.

Note that when you get to 95% the charge current is already reduced and you could simply use a dc-dc converter to finish charge it to 100% if solar isn’t an option. Most of my diagrams are solar oriented because I’m always in or near the tropics.

And what happens if eg the main battery fuse fails or any other reason the BMS cuts the LiFePo4, you have in worst case in parallel an alternator and the DC generator creating a huge surge spike not only damaging both.
The reason he chose argofet.
If he wants to get rid off lead starter, your solution with adding surge protectors to both alternator and dc gen is the way.
If he keeps the starter using argofet is the simpler and safer solution.
And yes to optimse charge of the lead starter he can use additional his 9A DC2DC charger to the starter from the lifepo4 and to keep it floated when alternator/dc gen is not running.

[CaptainRivet]

Originally Posted by newhaul

Post your own diagrams please would like to see how you have your system setup .

Simple:
Per hull: 115A Mitsubishi (soon 2 and both re-geared from 2:1 to 3.3:1, bracket in farbrication) to 200A argofet, output to lifepo4 house and LTO starter with an 5A Heltec balancer and older generation ElectrodacusBMS reused (therefor was cheaper then a BMV712 i would normally use in this setup) to do cell monitoring of LTO and LVC at 6V and HVC at 18.5V by cutting sense wire of alternator
ElectrodacusBMS lifepo4 house cuts the sense wire of alternator when 95%SOC reached or desaster happens. Solar does rest.
BMV712 as last resort for lifepo4 house in case BMS fails also cutting sense wire. A battery selector and join switch ( 1 or 2 or 1+2) between Lifepo4 and LTO, so can charge LTO in case no engine avaliable or LTO as emergency backup for house.
No hard battery cut off possible except main Lifepo4 battery fuse fails/releases but nothing happens as LTO is still there.
Yes LTO starter is never 100% SOC, max 85% but compared to Lifepo4 you can balance it at any SOC state and keep it at any SOC you want as long as you want. The 85%SOC means its always available to get more charge. Self discharge is neglectable like lifepo4.

[newhaul]

Originally Posted by CaptainRivet

Simple:
Per hull: 115A Mitsubishi (soon 2 and both re-geared from 2:1 to 3.3:1, bracket in farbrication) to 200A argofet, output to lifepo4 house and LTO starter with an 5A Heltec balancer and older generation ElectrodacusBMS reused (therefor was cheaper then a BMV712 i would normally use in this setup) to do cell monitoring of LTO and LVC at 6V and HVC at 18.5V by cutting sense wire of alternator
ElectrodacusBMS lifepo4 house cuts the sense wire of alternator when 95%SOC reached or desaster happens. Solar does rest.
BMV712 as last resort for lifepo4 house in case BMS fails also cutting sense wire. A battery selector and join switch ( 1 or 2 or 1+2) between Lifepo4 and LTO, so can charge LTO in case no engine avaliable or LTO as emergency backup for house.
No hard battery cut off possible except main Lifepo4 battery fuse fails/releases but nothing happens as LTO is still there.
Yes LTO starter is never 100% SOC, max 85% but compared to Lifepo4 you can balance it at any SOC state and keep it at any SOC you want as long as you want. The 85%SOC means its always available to get more charge. Self discharge is neglectable like lifepo4.

Not what I was asking for what I'm asking for is your reference diagrams of your setup.

[s/v Jedi]

Originally Posted by CaptainRivet

Jedi's strategy/philosophy in nearly all his diagrams is to only have the alternator function savely with lifepo4 delivering a fraction of what it could actually do and have solar do the maximum. His diagrams are really good except the alternator solution and that's philosophy should be standing in thick bolt printed red letters underneath in this diagrams.
I strongly disagree with this strategy/philosophy as its a) waiting resources, b) wasting money an c) reduces safety as the alternator is not a real backup anymore and d)often complicate things that introduce additional failure points.

My philosophy is always try to get safely max out of the existing alternator as simple as possible and as cost efficient as possible independent if it's the main charge source or 3rd backup. If the engine runs their is no reason to waste charge from the alternator as long as the battery is not full. A simple switch in the sense wire to shut it off to free spinning when full engine power is needed on a small engine is in 95% cases sufficent.
Eg. DC2DC charger as well as a Wakespeed regulator have their clear purpose where it really makes sense to use them but both are often misused or used when a much simpler and/or economical solution could be used that delivers more output for the same money and/or is saver due to simpler with less failure points.

That’s a pretty bold statement in my thread that is about using the alternator to directly charge the lithium battery. This shows that you have it completely backwards, it would be humorous to just let you dig a deeper hole but I’ll protect you a bit here.

So as there ain’t many BMS systems that allow my proposed setup and those that do are expensive, I have brought forward an alternative that is very easy to do for those who have a Victron battery monitor or Cerbo with programmable internal relay. This alternative allows full power alternator charging of the lithium batteries without needing lead acid batteries in parallel, without needing battery isolators, without using incompatible charging profiles etc. so it is simple and effective.

So please stop saying that I don’t support charging lithium from the alternator because it is false and it is misinformation that doesn’t belong on this forum.

Do I love charging from alternators? H… no! You need to run an internal combustion motor to spin the alternators and this is straight against my ideas about sailboats that are self sufficient and use green solar energy instead of burning diesel. But that doesn’t mean I don’t have a good setup for my alternator.

[CaptainRivet]

Originally Posted by newhaul

Not what I was asking for what I'm asking for is your reference diagrams of your setup.

Don't have a reference diagram for that at the moment. Busy with a lot last projects before crossing and continuing my world circum that was interrupted by corona and therefor no time to make one now. Will do when I have time.
That's the description of the diagram, just make one out of this if you fancy to have one now.

[newhaul]

Originally Posted by CaptainRivet

Don't have a reference diagram for that at the moment. Busy with a lot last projects before crossing and continuing my world circum that was interrupted by corona and therefor no time to make one now. Will do when I have time.
That's the description of the diagram, just make one out of this if you fancy to have one now.

I will wait as I'm not asking for myself but rather everyone that reads this thread to be able to refer to when specific differences are referenced in posts jedi posted his I have posted my sketch. Mine doesn't look great but it is a good reference. Also have posted dimple diagram that Maine sail made on his website. Visuals make it easier for many to understand the nuanced issues .

[CaptainRivet]

Originally Posted by s/v Jedi

That’s a pretty bold statement in my thread that is about using the alternator to directly charge the lithium battery. This shows that you have it completely backwards, it would be humorous to just let you dig a deeper hole but I’ll protect you a bit here.

So as there ain’t many BMS systems that allow my proposed setup and those that do are expensive, I have brought forward an alternative that is very easy to do for those who have a Victron battery monitor or Cerbo with programmable internal relay. This alternative allows full power alternator charging of the lithium batteries without needing lead acid batteries in parallel, without needing battery isolators, without using incompatible charging profiles etc. so it is simple and effective.

So please stop saying that I don’t support charging lithium from the alternator because it is false and it is misinformation that doesn’t belong on this forum.

Do I love charging from alternators? H… no! You need to run an internal combustion motor to spin the alternators and this is straight against my ideas about sailboats that are self sufficient and use green solar energy instead of burning diesel. But that doesn’t mean I don’t have a good setup for my alternator.

Your reference diagram is based on fully external regulated alternators and needs additonal 2x DC2DC chargers that are easily fooled by other charge equipment.
You don't need charge profiles for a lifepo4, it live's easily 15 years with just a simple powersupply charging it to 13.8V and then charge cut by a battery monitor. And you also need no profil when you cut at 95% as you suggested as thats still bulk stage which doesn't matter if there is a FLA, AGM or Lifepo4 charge profile at the alternator.
It's not a lead and lifep4 just takes and regulate by itself what is needed.

My setup takes unmodified stock alternators or any externally regulated alternator with just the prerequisite of working internal temp control.
It keeps factory warranty on newer Volvo's which is not possible with your approach as you have to modify the MDI box.
The argofet isolates the alternator from house and starter, so a disconnect spike can only damage the alternator.
No wrong profiles can be set or manipulated.
No DC2DC chargers that will be fooled by other charge equipment.
Alternator just do bulk charge till 95%, so again the charge profil in the alternator is obsolete and doesn't matter.
Just for completeness the 115A Mistubishi AGM regulator on any marine engine has a 14.2V regulator and is fully sufficent to charge a lifepo4 to 100%SOC but its a) not efficent and b)the risk of a cutoff by lifepo4 bank raises exponentially sue to any reason above 95% SoC so it's better not to do it as with any other regulated alternator as you also state.
It's much cheaper, simpler and saver then your solution for 95% of users.

The other 5% are yachts with a huge regulated alternator only where you really make use of the charge profil in the regulator to fully charge it in all stages and don't stop at 95% SoC.

And yes I don't like charging with alternators either BUT when the engine is running I like to get all the existing alternator can do to charge the oversized bank and spend the less money possible to achieve that.

[newhaul]

Originally Posted by CaptainRivet

No DC2DC chargers that will be fooled by other charge equipment.

.

Please explain to me how the DC2DC when properly installed To run from engine and start bank side to your lifepo4 bank
could possibly be fooled by other charge equipment?

[s/v Jedi]

Originally Posted by CaptainRivet

Your reference diagram is based on fully external regulated alternators and needs additonal 2x DC2DC chargers that are easily fooled by other charge equipment.
You don't need charge profiles for a lifepo4, it live's easily 15 years with just a simple powersupply charging it to 13.8V and then charge cut by a battery monitor. And you also need no profil when you cut at 95% as you suggested as thats still bulk stage which doesn't matter if there is a FLA, AGM or Lifepo4 charge profile at the alternator.
It's not a lead and lifep4 just takes and regulate by itself what is needed.

My setup takes unmodified stock alternators or any externally regulated alternator with just the prerequisite of working internal temp control.
It keeps factory warranty on newer Volvo's which is not possible with your approach as you have to modify the MDI box.
The argofet isolates the alternator from house and starter, so a disconnect spike can only damage the alternator.
No wrong profiles can be set or manipulated.
No DC2DC chargers that will be fooled by other charge equipment.
Alternator just do bulk charge till 95%, so again the charge profil in the alternator is obsolete and doesn't matter.
Just for completeness the 115A Mistubishi AGM regulator on any marine engine has a 14.2V regulator and is fully sufficent to charge a lifepo4 to 100%SOC but its a) not efficent and b)the risk of a cutoff by lifepo4 bank raises exponentially sue to any reason above 95% SoC so it's better not to do it as with any other regulated alternator as you also state.
It's much cheaper, simpler and saver then your solution for 95% of users.

The other 5% are yachts with a huge regulated alternator only where you really make use of the charge profil in the regulator to fully charge it in all stages and don't stop at 95% SoC.

And yes I don't like charging with alternators either BUT when the engine is running I like to get all the existing alternator can do to charge the oversized bank and spend the less money possible to achieve that.

No. There is only one little dc-dc charger for the starter battery and it’s only needed when it is a different chemistry.

[CaptainRivet]

Originally Posted by s/v Jedi

No. There is only one little dc-dc charger for the starter battery and it’s only needed when it is a different chemistry.

Well I see here 2x DC2DC in the reference diagram providing charge to the starter curcuit or one charges starter and the other charging LFP, not clear from the diagram in which way they are connected.
And if you have LFP starter then surge protectors would be needed if there is no lead.
Also how do you realize that the starter if LFP too is not discharged into house if there are no DC2DC, the only way I know besides DC2DC is a splitting diode aka Argofet.

[chowdan]

First - thanks all for the comments and help and information.

Secondly - i will not feed into arguments or debates about whats right or wrong and to each their own on how they operate their boat - just like to each their own if they choose to drive a vehicle on a freeway at 80mph when its posted at 60mph.


I am going to be operating a system as Jedi has posted but I will be using an argofet - with my discounts it is negligeable cost and provides me with a failsafe mechanism that removes the stress/worry that my BMS settings may be slightly off or I make an oppsie mistake. When/if i decide to replace the starter with LFP i will re-evaluate and go from there. It wont be a difficult thing to do.

Batteries arrive today in a few hours. I return to the boat tomorrow evening from house sitting + all my other work/tasks to do means that I probably wont be starting the build until atleast next week(unless i return to dead batteries - likely).

BMS settings I am planning on using are as follows(still under research/investigation)

Batteries: 8xEVE 314ah MB31 cells (spec sheet that was sent to me says they pulled 331ah) - 2 x 4 = total 628ah @ 12v each.
BMS: 2xJK BMS - 4s 200amp w/2amp active balancer + bluetooth and heating pad capable

Max voltage: 3.65v
BMS Over volt charge cut out point: 3.60v
Charger "complete" absorption voltage: 3.55v
Charger Float: 3.40v
Load low voltage cut off: 3.0v
BMS under volt cut out point: 2.88v
BMS single cell under volt cut out: 2.63
Min low voltage: 2.55v


These numbers will be multiplied by 4 for things like the multiplus, balmar, mppt to get 12v basis numbers/settings. I will be relying on the multiplus & the MPPT(and likely the DC genset regulator though it probably wont ever run that long to get there) to get cells to 3.55v - IE into float. May bump numbers up/down a bit to reduce stress on them as dead of winter time my 700w solar gives me a glorious 50w of power if i'm lucky.

Apologize for the thread drift, but figured others who come across this at some point in the future might like to see planned settings

[newhaul]

Originally Posted by CaptainRivet

Well I see here 2x DC2DC in the reference diagram providing charge to the starter curcuit or one charges starter and the other charging LFP, not clear from the diagram in which way they are connected.
And if you have LFP starter then surge protectors would be needed if there is no lead.
Also how do you realize that the starter if LFP too is not discharged into house if there are no DC2DC, the only way I know besides DC2DC is a splitting diode aka Argofet.

Looks to me like one 30 amp dc2dc for each AGM start battery .
Look at the drawing the heavy red vs the thin red lines
The alternator is on the same positive busbar as the lifepo4 bank