LiFePO4 reference diagram, Alternator version

[CaptainRivet]

Originally Posted by Cheyne

You provide great comic relief. Keep it up.

No comic, the right way of connecting a Valeo 125A who protects itself, a DC2DC is useless and waste of money.

[newhaul]

Originally Posted by CaptainRivet

Neither simple, nor bulletproof.
Simple is connecting both in parallel out 1 and out 2 to the argofet, alternator to in and forget about it. Nothing to adjust or to worry about.

No losses, no wrong parameter you can set, no charge limit that castrate the alternator and half the cost for nearly double the output plus no output if the DC2DC is broken.
If the AGM breaks and gets an internal cell short (most common due to sulfaltation) and you charge AGM directly via alternator then to 50A DC2DC to LFP, the AGM will get a thermal runaway. In parallel to an LFP via argofet, it won't as it has no load on it and therefor only very small discharge but protects with its high resistance if the LFP switches off. That's why if you use a DC2DC take a FLA, that will only gas out while an AGM will get thermal runaway, not many know...
Don't know anyone who broke an argofet but several who killed an DC2DC.

It's simple you didn't know the Valeo has internal temp protection and protects itself and thought it's a dumb alternator that need to be limited in output by a DC2DC to protect it.

Explain in simple terms how this system is not the most simple and hence bulletproof.

Stock internally regulated alternator to FLA to dc/dc to LIFEPO4. It's literally a positive and negative wire in from start bank to dc/dc a control wire to ignition and a positive wire and negative wire from dc/dc to LIFEPO4. .

[Cheyne]

Originally Posted by CaptainRivet

No comic, the right way of connecting a Valeo 125A who protects itself, a DC2DC is useless and waste of money.

Na, you are one when it comes to right and wrong should be ignored. Your no nothing thread on MPPT's showed this with flying colors. In the local parlance...Bless your heart.

Cheyne

[CaptainRivet]

Originally Posted by newhaul

Explain in simple terms how this system is not the most simple and hence bulletproof.

Stock internally regulated alternator to FLA to dc/dc to LIFEPO4. It's literally a positive and negative wire in from start bank to dc/dc a control wire to ignition and a positive wire and negative wire from dc/dc to LIFEPO4. .

That's simple words above.
The argofet is simply connect the cable from alternator to argofet, out to both batteries, job done and nothing to adjust. And as I explained if you have AGM starter no runaway as no load on it.

DC2DC connecting is the same, just splitting cable after starter then before. Now you need to adjust the profile, you can select wrong values or if XS connected via VE-direct with cerbo and DVCC is enabled that even overwrite the value it measures from LFP...and several other possibilities of wrong adjustments. Where you can adjust you can do wrong and you find on google dozen examples people using DC2DC and charge LFP with wrong profile...
As I wrote if an AGM is connected you can get thermal runaway and burn your boat down if you not discover it early enough and toss it overboard.
Not happening with an FLA other its gassing out and damage done by that. But AGM is highly recommended everywhere as starter and to use with DC2DC.
If the DC2DC breaks no alternator charge and they do break/fail, never heard of an argofet failing and Google search also brings nothing up.

So with DC2DC you castrate the alternator unnecessarily (you wanna have as much charge as savley possible from your alternator) and several more failure possibilities plus also not as bulletproof as the simple argofet.
Only prerequisite your alternator must have temp protection which the stock Valeo 125A and the stock 115A Mitsubishi has, then argofet is the simpler, cheaper and more bulletproof way then DC2DC with always the max save output the alternator can do. So no reason going DC2DC in this case.

[s/v Jedi]

Originally Posted by newhaul

Here is an honest question for those that may actually know and please concise answers please
Limited bandwidth and all
I can get a 12v 1500 watt PMA how good would that do for charging my 250ah 12v lifepo4 house bank running directly off a small engine in a belt drive genset type setup?will it survive ?
I can get a 2kw unit as xwell for not much more .

Is that a Permanent Magnet Alternator? I don’t think I ever saw one in my life

[s/v Jedi]

About the new Victron 50A DC-DC charger: the reason it runs much cooler is because of its high efficiency, namely 98.5% which is a radical improvement.

But.. that doesn’t mean it doesn’t get hot. It may seem so at first but that can be because it has a much larger 50A capacity compared to the 30A of the previous models so it my run at a lower load percentage.
Much of the efficiency improvement has resulted in a smaller heatsink so it still gets hot when running at full load, even though it my take longer before reaching that higher temperature.

Like the older generation, it will automatically throttle back when the temperature rises too high, so the unit is protected against overheating.

I do recommend this unit and hope to see many versions being launched for different voltages. But I also still recommend to mount this on a fiberglass surface, not on wood without fiberglass skin. If you don’t have a suitable surface, simply buy a 3/16” thick piece of GPO3 fiberglass which is made for exactly this, affordable and available here: https://www.mcmaster.com/products/sh...-fiberglass-1/

Also, I recommend to use crimped ferrules for all connections to all equipment with screw terminals, even when the terminals allow for wire without ferrules. You can buy tools and ferrules on Amazon, also larger sizes like 8AWG and 6AWG. Note that the (cheap) crimp tool may not be big enough for those. If that happens to me, I first crimp with a hex crimper for coax connectors that I have at hand, after which it fits the ferrule crimper. It’s better to buy the correct ferrule crimper of course, but remember that this crimp is not critical because the screw terminal will completely crush it. The main purpose of the ferrule is to keep all strands together in a straight bundle and protect them against damage.

[Cheyne]

I have added a fan controlled by a temp sensor/relay to move air over mine also.

I whole heartly agree with the ferrules. 6 awg ferrules were a tight fit on the new 50 amp compared to the old 30 amp, but they do go in. Round hole and square peg thing.

Behind my DCDC I have cement backerboard that I had left over from our house electrical upgrade. I cut a 12"x12" piece and bolt it to the wall and then screwed my DCDC to it. Same for my inveter/charger and MPPT's. I'm assuming this is okay on a boat.

Cheyne

[newhaul]

Originally Posted by s/v Jedi

Is that a Permanent Magnet Alternator? I don’t think I ever saw one in my life

Yes PM alternator. What you do is open the rotor and replace the wire electromagnet with doughnut magnets salvaged out of old microwave ovens .
But the ones I'm talking about here are commercial available a 1500 watt 12v unit is about $100

[newhaul]

Originally Posted by CaptainRivet

That's simple words above.
The argofet is simply connect the cable from alternator to argofet, out to both batteries, job done and nothing to adjust. And as I explained if you have AGM starter no runaway as no load on it.

DC2DC connecting is the same, just splitting cable after starter then before. Now you need to adjust the profile, you can select wrong values or if XS connected via VE-direct with cerbo and DVCC is enabled that even overwrite the value it measures from LFP...and several other possibilities of wrong adjustments. Where you can adjust you can do wrong and you find on google dozen examples people using DC2DC and charge LFP with wrong profile...
As I wrote if an AGM is connected you can get thermal runaway and burn your boat down if you not discover it early enough and toss it overboard.
Not happening with an FLA other its gassing out and damage done by that. But AGM is highly recommended everywhere as starter and to use with DC2DC.
If the DC2DC breaks no alternator charge and they do break/fail, never heard of an argofet failing and Google search also brings nothing up.

So with DC2DC you castrate the alternator unnecessarily (you wanna have as much charge as savley possible from your alternator) and several more failure possibilities plus also not as bulletproof as the simple argofet.
Only prerequisite your alternator must have temp protection which the stock Valeo 125A and the stock 115A Mitsubishi has, then argofet is the simpler, cheaper and more bulletproof way then DC2DC with always the max save output the alternator can do. So no reason going DC2DC in this case.

I have seen hundreds of those batter it's warranty. y insulators fail in the rv industry . I personally had a couple fail. One was installed to isolate and also charge my house battery on my camper. ( show me one single unit that actually will survive in a marine environment that will not violste
Agm is a no go for me it's to damn expensive as a throwaway. Now explain the actual difference between the two (dc/dc and s battery isolator ) without the word salad that I asked you to not post on reply to my query

[wholybee]

Originally Posted by newhaul

I have seen hundreds of those batter it's warranty. y insulators fail in the rv industry . I personally had a couple fail. One was installed to isolate and also charge my house battery on my camper. ( show me one single unit that actually will survive in a marine environment that will not violste
Agm is a no go for me it's to damn expensive as a throwaway. Now explain the actual difference between the two (dc/dc and s battery isolator ) without the word salad that I asked you to not post on reply to my query

Your install is perfectly fine, proven and the way many if not most installs are done.

FLA is better than AGM in most cases because it is less sensitive to damage caused by undercharging, and you can reverse some of that damage with an EQ charge that won't work with AGM.

As for the difference between an isolator and a DCDC. The DCDC limits the current to a max of 30A (or whatever the rating of your DCDC is) and provides a programmable charge profile to match any chemistry. The isolator allows max alternator output for faster charging, but then also does not have the programable charge profile.

I think the programable profile is important. Do you know the voltage of your alternator? Is it the same as the voltage you have your DCDC set for? Probably not!

[newhaul]

Originally Posted by wholybee

Your install is perfectly fine, proven and the way many if not most installs are done.

FLA is better than AGM in most cases because it is less sensitive to damage caused by undercharging, and you can reverse some of that damage with an EQ charge that won't work with AGM.

As for the difference between an isolator and a DCDC. The DCDC limits the current to a max of 30A (or whatever the rating of your DCDC is) and provides a programmable charge profile to match any chemistry. The isolator allows max alternator output for faster charging, but then also does not have the programable charge profile.

I think the programable profile is important. Do you know the voltage of your alternator? Is it the same as the voltage you have your DCDC set for? Probably not!

Group 24 FLA start battery
The 75 amp alternator runs at standard 14.6v
My 40 amp renogy dc2dc is set to my preferred lifepo4 bank set point of 14.0v ( 250ah house battery)
I considered the 50 or 60 amp units but got a half price deal on the 40 amp unit . Factory open box sale . I know my setup is better than many as I used to do this for a living .

[svloki]

Originally Posted by newhaul

I will keep my FLA
Alternator to fla to dc dc to LIFEPO4. Set dc dc to 13.8 so no HVC disconnect even possible . All is good why complicate a simple thing .
My boat and all

This seems a good solution for alternators with lower output.

If you run a much higher output does it make sense to then take advantage of the very high rate of charge that the lithium can accept by connecting your alternator to the lithium bus, and let a small (cheap) dc-dc charger handle the lead acid battery charging? I think this is what Jedi had in mind with his diagram.

Yes, you would complicate things with an alternator disconnect, but you get a massive rate of charge as a benefit.

[newhaul]

Originally Posted by svloki

This seems a good solution for alternators with lower output.

If you run a much higher output does it make sense to then take advantage of the very high rate of charge that the lithium can accept by connecting your alternator to the lithium bus, and let a small (cheap) dc-dc charger handle the lead acid battery charging? I think this is what Jedi had in mind with his diagram.

Yes, you would complicate things with an alternator disconnect, but you get a massive rate of charge as a benefit.

If I want more charge I would start my 1500watt genset and run my 120 amp inverter charger charging side.

For high output ( over 120 amp output ) yes hook up to your lifepo4 bank through an external regulator of some type .

In my experience most with the 150 amp and above alternator don't actually use them on any regular schedule for charging . Solar is to cheap and quiet . 20 years ago yes but today not so much .

[CaptainRivet]

Originally Posted by wholybee

Your install is perfectly fine, proven and the way many if not most installs are done.

FLA is better than AGM in most cases because it is less sensitive to damage caused by undercharging, and you can reverse some of that damage with an EQ charge that won't work with AGM.

As for the difference between an isolator and a DCDC. The DCDC limits the current to a max of 30A (or whatever the rating of your DCDC is) and provides a programmable charge profile to match any chemistry. The isolator allows max alternator output for faster charging, but then also does not have the programable charge profile.

I think the programable profile is important. Do you know the voltage of your alternator? Is it the same as the voltage you have your DCDC set for? Probably not!

Programmable Profil is not important with lifepo4 for an alternator, you want it to charge the bulk phase and then shut off to avoid a disconnect. Absorption and float is not needed on lifepo4, with bulk only it’s 99% SOC and to balance it from time to time solar does much better job then alternator.
and the AGM regulator of Valeo 125A and 115A Mitsubishi (both stock on newer Volvo,Yanmar,Beta with Serpentine belt drive) works perfectly, it’s adjusted to 14.2V so won‘t overcharge lifepo4, additionally there is a voltage drop on cable and argofet so the lifepo4 gets perfect 14.0V max.
You can compensate that with running a sensewire to argofet but I don’t as the voltage drop is welcomed here as adding additional security margin not to overcharge the lifepo4 should the cutoff at 99%SOC (or earlier) fail due to any reason. And if your alternator has an FLA regulator with temp protection you can use the argodiode which has 0.3V voltage drop instead argofet which reduces the voltage from typically max 14.7V to save 14,4V - cable voltage drop.
Again simple, bulletproof, effective and even cheap IF your alternator has temp protection.

Another issue with DC2DC, especially the Victron is its voltage based alternator run detection which gets easily fooled by other charge sources resulting in draining the starter, even if you are working additionally with an ignition wire.
Cannot happen with an argofet.
The solution to this problem is the easy AS alternator relay which scans for the typical ripple only an alternator produces and only if it’s sensing that ripple it’s switching on the DC2DC, not sensing that anymore switching it off. Like this you can use the cheaper renogy DC2DC chargers (or other budget ones) and spare yourself running an ignition wire, which can get complicated and you need to hack into original wiring but still can cause unwanted draining of starter without this relay.

[CaptainRivet]

Originally Posted by svloki

This seems a good solution for alternators with lower output.

If you run a much higher output does it make sense to then take advantage of the very high rate of charge that the lithium can accept by connecting your alternator to the lithium bus, and let a small (cheap) dc-dc charger handle the lead acid battery charging? I think this is what Jedi had in mind with his diagram.

Yes, you would complicate things with an alternator disconnect, but you get a massive rate of charge as a benefit.

DC2DC makes sense for dumb alternator with low output eg the 80A Hitachi found on many older engines from eg Volvo and simple boats with no big energy needs.
Corret charging LFP directly with an externally regulated alternator and use a small DC2DC to float the lead starter from LFP is the common solution.

Or with a big regulated alternator you can delete the lead starter and replace it with a Lifepo4 starter, more and more budget lifepo4 starter coming to market or with cell prices of 70Euro for grade B 280Ah or 304AH EVE plus eel kit build yourself a 280AH lifepo4 starter for below 500Euro which works also great as backup to the lifepo4 house. In this case you again use an argofet to isolate the lifepo4 starter plus a surge protector, so the house cannot drain starter which happens if you simply parallel them and the alternator doesn‘t get destroyed when both independent lifepo4 disconnect due to the surge protector.