Charging 1 LFP + 1 Optima with charger and alternator

[M'Enfin]

Hi

I'm new here and having a question/problem

No one could give me the solution till now

This concerns my sailboat electricity

I have

4 cells 12v 200amp Aliexpress batteries - living / electronic / fridge

1200.0US $ |Lot De 4 Batteries Lifepo4 De Qualité A, 3,2 V, 200ah, Rechargeables, Cellules À Code Qr, 12v, 24v, 48v, Pas De 280ah, Pour Camping-car, Solaire, Marine, Eu, Us, Sans Taxe, Nouveauté 2021 - Batteries Rechargeables - AliExpress

Achetez malin, vivez mieux! Aliexpress.com

fr.aliexpress.com

1 Daly 4s 12v 250amp BT BMS

179.72US $ 20% de réduction|BMS intelligent 4s 200A avec Bluetooth pour batterie au lithium, outil de stockage d'énergie solaire avec application UART, 250 LifePO4 de 12 V, livraison partout en Pologne | AliExpress

Achetez malin, vivez mieux! Aliexpress.com

fr.aliexpress.com

1 Optima 76amp battery - engine

YELLOWTOP® D31A

The YELLOWTOP® D31A is a high-performance AGM battery designed to deliver a strong burst of ignition power for a reliable start-up. Discover YELLOWTOP® today!

www.optimabatteries.com

1 Victron 12/200/3 - 30amp smart charger

Blue Smart IP22 Charger - Victron Energy

The Blue Smart IP22 Charger is the new professional battery charger with built-in bluetooth. Find a Victron Energy dealer near you.

www.victronenergy.com

On my Yanmar engine I have a 45amp alternator

The Smart charger can charge my Optima and LFP battery

But, I do not know wich DC/DC charger to buy to charge via the alternator

I'm thinking to

Renogy DC/DC - 20amp

12V 20A DC to DC On-Board Battery Charger

The best 12v battery charger. Free shipping. The DC-DC Battery Chargers are the most effective method to charge your home batteries from the starter battery

www.renogy.com

Victron Smart DC/DC Orion 20amp

Orion-Tr DC-DC Converters Isolated - Victron Energy

Provide a stable DC output voltage using the, easy to install, Orion DC-DC Inverter from Victron Energy. Find a dealer near you.

www.victronenergy.com

Heeeeeeeeeeeeeeeeeeeeeeeeeeeeelp

Thanks for all

Camille
Bruxelles - Belgium

 

[DJSmiley]

I would go for the Victron. The alternator also has to charge/power other items like the starter battery most likely, and I won't recommend pushing it to its max.

The Victron is way better quality than the Renogy, and unlike the Renogy, fully adjustable.

You don't need an isolated one, the regular non-isolated will work just as fine for your application.

Important: The Orion range exists of both DC-DC converters and chargers.
The one you're linking is NO charger, but a 'stupid' DC converter. It lacks any charging profiles.

You do need the Orion Smart, those can be used as chargers and do have the proper characteristics for properly charging a LFP.

You need https://www.victronenergy.com/dc-dc-converters/orion-tr-smart-non-isolated

 

[M'Enfin]

Waouw
This is a fast answer

Thanks for showing my error. I'm totally lost for the moment.

I explained my pblm at Victron, and they sold me a BMS CL 12/200. Valid only for victron batteries. 279€ lost

I knew I need a charger but I do not know what to buy ?

I've been told that a 30amp would be too powerful for my small alternator.

But, why not a "smart"? Isn't this useful to specify the type of charge I need?

 

[mizermizer]

I just went though a build of almost this same configuration. We finally got it all ironed out, and it has been running for a few months now. Our setup included solar.

Yes, the start battery (Optima) and the house battery (LFP) must be isolated from one another. They can, and probably do, share the same ground. The Victron charger fits in between them. Orion-Tr Smart 12/12 - 18 amp, isolated or non-isolated, for you doesn't matter. Your alternator chargers your Optima, and supplies the current for the Victron Charger to in turn charge the LFP.

Where it gets tricky is to understand all your loads, especially the dynamic loads while underway, while trying to use the alternator and Victron Charger to 'run' the boat, and charge the battery(ies) at the same time. That is where I got into a bit of trouble, and had to move up to the 30 amp version of the Orion-Tr Smart. But I have a 60 amp alternator.

You have a 45 amp alternator and if you were to pull 30 amps continuous from it, I think where you would get into trouble would be at idle. At low rpm's that alternator would get HOT.

You should try to draw up a block diagram, that includes all your loads. Showing which battery is going to run which loads. I attached an early concept drawing I made. It's close to the 'as built', but not exact. Also some photos of the way it turned out. My hands hurt after that build!

 

[mizermizer]

And Yes go Victron. Good hardware. Assuming you have only one ground for the whole boat (very likely), on the isolated version of the charger it is safe to tie the input GND to the output GND.

 

[DJSmiley]

But the non-isolated version is cheaper, so unless you want to get rid of your money the isolated version with connecting both gnds is pretty useless

Going for the 18 or 30A version depends on the load on the alternator. If it's a dedicated alternator for the household battery, you can go with the 30A. If the alternator is shared (thus providing charge to the starter battery and other boat equipment) I would suggest the 18A version

Victron stuff is great quality, but it's intended to be used in the victron ecosystem (in which it works great). Their BMS is such an example. With all Victron gear: awesome. But useless (or limited) if it needs to work with other vendors.

But, why not a "smart"? Isn't this useful to specify the type of charge I need?

You do need the smart, since that one can act as a charger: Thus charging to a set voltage (14.2V by default with the Victron LFP settings) and than stop charging (or go to a low float to maintain providing power to the load).

A DC-DC convertor (without charging profiles) needs to be set to eg 13.6, but it never would charge the battery completely (and you won't get much current due to the low voltage difference).
When set to 14.2V, yes, it works as a charger. But if the current drops to almost zero (cells are fully charged) it will continue to provide 14.2V, eventually overloading the cells. It needs to stop at that point, which it doesn't since it's not a charger

 

[mizermizer]

DJ & Enfin: I think you'll find the 12/12-18 Orion-Tr Smart is only available in the isolated version. For whatever reason Victron only makes it that way, best I can tell.

If you don't always have access to shore power, here's something to think about. I notice you are running the living / electronics / and fridge from the LFP. Let's guess at the amps needed to do that: living (maybe lights only) - 2 amps, electronics - 6 amps (depends what you have of course - radio(s), chart, sonar, radar), and fridge - 5 amps. So, after spending the night on board, you wake up in the morning, LFP battery mostly depleted, you have breakfast, then start your motor, and begin underway. The Orion sees the start battery voltage come up, and starts trying to charge the LFP. But add it up, 13 of the 18 amps from the charger is being used to run those items. That 13 amps, out of your 18, is not available to charge the battery. So, in that scenario, you're only left with 5 amps to charge your possibly depleted LFP battery. If you run all day you'd still only end up with 40 amp-hrs charge in your battery. Maybe not what you're expecting.

Now I don't know your operating scenarios, but you can see after a day or two of the above, the LFP ends up dying in the middle of the night two! Maybe you always have access to shore power, so maybe this can't happen to you. But I thought I'd mention it.

Anyway that's some food for thought for ya.

 

[M'Enfin]

Hello.
Some more info.
The charger is only use with 220v shore power.
So both charge source are never use together.
The engine never runs when I'm on shore power.

 

[M'Enfin]

I got it.

Indeed I need to charge both batteries

1st engine to regain the power I lost when starting

Then service

So I need the smart charger 18amp. As I have a small alternator

 

[M'Enfin]

I just went though a build of almost this same configuration. We finally got it all ironed out, and it has been running for a few months now. Our setup included solar.

Yes, the start battery (Optima) and the house battery (LFP) must be isolated from one another. They can, and probably do, share the same ground. The Victron charger fits in between them. Orion-Tr Smart 12/12 - 18 amp, isolated or non-isolated, for you doesn't matter. Your alternator chargers your Optima, and supplies the current for the Victron Charger to in turn charge the LFP.

Where it gets tricky is to understand all your loads, especially the dynamic loads while underway, while trying to use the alternator and Victron Charger to 'run' the boat, and charge the battery(ies) at the same time. That is where I got into a bit of trouble, and had to move up to the 30 amp version of the Orion-Tr Smart. But I have a 60 amp alternator.

You have a 45 amp alternator and if you were to pull 30 amps continuous from it, I think where you would get into trouble would be at idle. At low rpm's that alternator would get HOT.

You should try to draw up a block diagram, that includes all your loads. Showing which battery is going to run which loads. I attached an early concept drawing I made. It's close to the 'as built', but not exact. Also some photos of the way it turned out. My hands hurt after that build!

Underway I only charge with the alternator.

Engine Optima is only used for the engine
LFP is only used for service

I never use Optima for service and LFP for engine start

In case the Optima gets unloaded, I have a switch to use the LFP

But this is just an emergency switch. Not supposed to be used as LFP are not made for this

 

[M'Enfin]

I just went though a build of almost this same configuration. We finally got it all ironed out, and it has been running for a few months now. Our setup included solar.

Yes, the start battery (Optima) and the house battery (LFP) must be isolated from one another. They can, and probably do, share the same ground. The Victron charger fits in between them. Orion-Tr Smart 12/12 - 18 amp, isolated or non-isolated, for you doesn't matter. Your alternator chargers your Optima, and supplies the current for the Victron Charger to in turn charge the LFP.

Where it gets tricky is to understand all your loads, especially the dynamic loads while underway, while trying to use the alternator and Victron Charger to 'run' the boat, and charge the battery(ies) at the same time. That is where I got into a bit of trouble, and had to move up to the 30 amp version of the Orion-Tr Smart. But I have a 60 amp alternator.

You have a 45 amp alternator and if you were to pull 30 amps continuous from it, I think where you would get into trouble would be at idle. At low rpm's that alternator would get HOT.

You should try to draw up a block diagram, that includes all your loads. Showing which battery is going to run which loads. I attached an early concept drawing I made. It's close to the 'as built', but not exact. Also some photos of the way it turned out. My hands hurt after that build!

If like to show a diagram. But the shipyard who installed everything did not do it. I'm quite angry against them for the moment.

 

[M'Enfin]

DJ & Enfin: I think you'll find the 12/12-18 Orion-Tr Smart is only available in the isolated version. For whatever reason Victron only makes it that way, best I can tell.

If you don't always have access to shore power, here's something to think about. I notice you are running the living / electronics / and fridge from the LFP. Let's guess at the amps needed to do that: living (maybe lights only) - 2 amps, electronics - 6 amps (depends what you have of course - radio(s), chart, sonar, radar), and fridge - 5 amps. So, after spending the night on board, you wake up in the morning, LFP battery mostly depleted, you have breakfast, then start your motor, and begin underway. The Orion sees the start battery voltage come up, and starts trying to charge the LFP. But add it up, 13 of the 18 amps from the charger is being used to run those items. That 13 amps, out of your 18, is not available to charge the battery. So, in that scenario, you're only left with 5 amps to charge your possibly depleted LFP battery. If you run all day you'd still only end up with 40 amp-hrs charge in your battery. Maybe not what you're expecting.

Now I don't know your operating scenarios, but you can see after a day or two of the above, the LFP ends up dying in the middle of the night two! Maybe you always have access to shore power, so maybe this can't happen to you. But I thought I'd mention it.

Anyway that's some food for thought for ya.

I'm not a big power user. I used to live 3 days with 2 75amp lead batteries. So, 200amp LFP is enormous for me.

I do not have a radar, sonar etc
Just the basics: depth, speed, wind, a small 7' plotter and sometimes the pilot

All lights are less, 10 for the all ship. Neve user more than 4 at the time

So the biggest consumer is the fridge, but never use at 100pct

 

[DJSmiley]

Underway I only charge with the alternator.

Engine Optima is only used for the engine
LFP is only used for service

I never use Optima for service and LFP for engine start

In case the Optima gets unloaded, I have a switch to use the LFP

But this is just an emergency switch. Not supposed to be used as LFP are not made for this

What is the current draw of the starter engine? I doubt if your BMS is capable of providing sufficient power to start. I think so, but I'm not sure. These are hugh current spikes.

Also, do you have solar? I've recently installed a 24V LFP setup in a boat, re-used the existing alternator regulator for charging. (It was a 24V setup - a larger boat). I also upgraded the MPPT controller to a Epever Duoracer. That one is also capable of charging a second (lead-acid) battery.


As for the isolated vs non-isolated: I didn't notice it, but it seems only the 30A version is available as non-isolated. Doesn't really matter, the isolated can be used for both setups, but I wasn't aware of this.

If you're also charging using shore power, please pay proper attention about galvanic isolation. On boats thats an important topic, depending on the material it's made of.

 

[tim0shel]

Sounds like it would be a good to upgrade the alternator on these boats https://js-alternators.com/

I have no builds as you do when it comes to being on a boat but we all can still learn something from it and I find it interesting.

 

[DJSmiley]

Upgrading alternators isn't that common here (At least, I don't know anyone who did here in NL). Also, it requires mounting and belts, so not so easy.

Since he is mentioning a sail boat, I assume the engine isn't always running. I'd suggest going for solar as addition to the alternator. 18A isn't that much, but probably sufficient when needed. And when charging by solar and/or shore as well, I don't really see the benefits of upgrading the alternator at this point (Considering the price involved)

 

[M'Enfin]

What is the current draw of the starter engine? I doubt if your BMS is capable of providing sufficient power to start. I think so, but I'm not sure. These are hugh current spikes.

Also, do you have solar? I've recently installed a 24V LFP setup in a boat, re-used the existing alternator regulator for charging. (It was a 24V setup - a larger boat). I also upgraded the MPPT controller to a Epever Duoracer. That one is also capable of charging a second (lead-acid) battery.


As for the isolated vs non-isolated: I didn't notice it, but it seems only the 30A version is available as non-isolated. Doesn't really matter, the isolated can be used for both setups, but I wasn't aware of this.

If you're also charging using shore power, please pay proper attention about galvanic isolation. On boats thats an important topic, depending on the material it's made of.

I have a 250amp BMS for 200amp battery
I suppose the engine will never aske 25amp. It used to start with a normal lead varta 75amp
It now starts with a 76ah Optima

 

[DJSmiley]

Capacity != current

A lead acid varta can provide 600A or so, any starter battery has a CCA rating, which indicates its maximum amps it can provide (under certain conditions).
LFP cells (Well, the prismatic ones we're commonly using) can provide less amps, usually it's 1C, sometimes 3C (Winstons for example). However, in the majority of the cases the BMS is the limiting factor.

Yes, even a 76Ah can provide 300A cranking amps... where as a 280Ah LFP with a 250A BMS can't. (the BMS just can't provide more)

 

[M'Enfin]

Upgrading alternators isn't that common here (At least, I don't know anyone who did here in NL). Also, it requires mounting and belts, so not so easy.

Since he is mentioning a sail boat, I assume the engine isn't always running. I'd suggest going for solar as addition to the alternator. 18A isn't that much, but probably sufficient when needed. And when charging by solar and/or shore as well, I don't really see the benefits of upgrading the alternator at this point (Considering the price involved)

More over this alternator is new. Mounted 2 months ago ?
Indeed, I run the engine to get out and get in the Marina. 1h a day.
I have 100w solar panel with a victron mppt to keep the batteries loaded. It works

 

[M'Enfin]

Capacity != current

A lead acid varta can provide 600A or so, any starter battery has a CCA rating, which indicates its maximum amps it can provide (under certain conditions).
LFP cells (Well, the prismatic ones we're commonly using) can provide less amps, usually it's 1C, sometimes 3C (Winstons for example). However, in the majority of the cases the BMS is the limiting factor.

Yes, even a 76Ah can provide 300A cranking amps... where as a 280Ah LFP with a 250A BMS can't. (the BMS just can't provide more)

I know

This is why I said that I would use the LFP to start the engine only in case of emergency.

A 76ah Optima provides 975ah CCA at start

 

[tim0shel]

More over this alternator is new. Mounted 2 months ago ?
Indeed, I run the engine to get out and get in the Marina. 1h a day.
I have 100w solar panel with a victron mppt to keep the batteries loaded. It works

To both that makes sense defiantly go for solar or as much as you can.