80A Alternator and 'drop in' LFP?

[Scrimma]

Hi all,

My new to me boat has 520ah fullriver AGM house battery capacity. These batteries are on their last legs and me thinks it's a great time to throw some LFP in instead. I'd like approx 400ah of Lithium at most.

Currently my 39hp yanmar has a 80A alternator on it. I've read that lithium will suck whatever an alternator can throw at it, in this case 80A. I also heard that alternators below 100A are made to run at 100% cycle and won't overheat and burn out like alternators over 100A. I can't for the life of me remember where i read/heard that recently, but I remember it being a fairly reputable source (in my limited opinion of the topic).

I have approx 660w of new sunpower panels that easily ram in 40+ amps when the sun pops out. Heck they were putting in 10amps in a rain storm yesterday which i was pretty pleased with. So I don't imagine i'll need to run the engine much to charge (especially with LFP) and I would probably run the little 1000w Generator instead unless I was motoring early in the morning etc leaving anchorages etc.

My question is, how 'DROP IN' are lithiums these days really? And will my alternator need regulating to say 60A to avoid overheating? How would I go about regulating that?

I have a AGM start battery and a VSR. I've changed the charging cable from the alternator to run directly to the house batteries instead of to the start battery and then through the VSR to speed up charging of the house. Will that cabling need changing? I think...that if my alternator is ok as it is, then unless i'm missing something (high chance of that) then I can drop in some LFP batteries (2x200ah approx) exactly where the AGM's are and plug and play...? Of course i'll get batteries with their own built in BMS to manage cells individually in each bank, but is there anything else to help this swap over go as smoothly as possible?

Oh and I do have a 240v Xantrex Truecharger 2 for generator plug in or shore power which doesn't have lithium charging algorithms so that will need to change too. Any tips on decent budget item for that? I currently use the Victron Smart Solar 100/50 MPPT and the Victron BMV-712 battery monitor, so I'm thinking something victron might make the most sense. I don't want a charger/inverter as I have a seperate 1000w inverter setup already for the rare times I need it.

I'm sorry if this all came across muddled.
This forum has been ridiculously helpful for my other projects.
Thank you in advance!
Scrimma

[john61ct]

Drop in is a myth. Prismatic cells of known good quality better way to go.

For longevity all sources must allow user custom profiles.

Or run them all through Sterling BB series DC-DC charger(s), which also limits current pulled.

Only special alts can run at anywhere near rating continuously, very rare.

Balmar MC-614 can de-rate.

Sterling Power ProCharge Ultra or ProMariner Pronautic P for shore charger.

But BBs mean no need to swap those.

[coopec43]

QUOTE: I also heard that alternators below 100A are made to run at 100% cycle and won't overheat and burn out like alternators over 100A. I can't for the life of me remember where i read/heard that recently, but I remember it being a fairly reputable source UNQUOTE

I'd be very surprised if that was correct. I just did a little research and came up with

The Most Common Cause of Alternator Failure

Did you know that out of all alternators fitted to cars, that over 85% will fail within 30 minutes of being fitted? This isn’t due to shoddy alternator design but is in fact due to shoddy mechanics not doing their job correctly.
So what are mechanics not doing correctly? Well, it all comes down to properly ensuring that the battery is fully charged. If the car battery is not charged, the alternator will fail to handle the vehicle's electrics and charge the flat battery. This is likely to result in an overloaded alternator. The rectifier will then blow and the unit will be rendered useless.

https://www.qxcomponents.co.uk/artic...ator-problems/

[Scrimma]

Originally Posted by john61ct

Drop in is a myth. Prismatic cells of known good quality better way to go.

For longevity all sources must allow user custom profiles.

Or run them all through Sterling BB series DC-DC charger(s), which also limits current pulled.

Only special alts can run at anywhere near rating continuously, very rare.

Balmar MC-614 can de-rate.

Sterling Power ProCharge Ultra or ProMariner Pronautic P for shore charger.

But BBs mean no need to swap those.

Thanks for the reply! Lots to contemplate there and much to google.

I just had a thought. If i was to swap my alternator cable back to my starter battery, remove the VSR so the alternator charges start battery only, replace the battery charger to one like you mentioned that will allow lithium custom charging like my MPPT...if i do all that, that should keep things pretty simple or no? That way i'll have the solar MPPT charging the lithium aswell as the little honda 1000w through the new lithium capable charger. That would keep all battery systems separate and avoid any AGM to Lithium complications and any need to change or play with alternator settings, dc-dc chargers etc.
Am i missing something in that setup?
To summarize;
1 - Change alternator charging cable back to start battery.
2 - Disconnect VSR so alternator will only ever charge start battery and never the lithiums
3 - upgrade battery charger that will now only operate under my 1000w generator or shore power.

Forgive my ignorance, but that seems like it might just work?

[Scrimma]

Originally Posted by coopec43

QUOTE: I also heard that alternators below 100A are made to run at 100% cycle and won't overheat and burn out like alternators over 100A. I can't for the life of me remember where i read/heard that recently, but I remember it being a fairly reputable source UNQUOTE

I'd be very surprised if that was correct. I just did a little research and came up with

The Most Common Cause of Alternator Failure

Did you know that out of all alternators fitted to cars, that over 85% will fail within 30 minutes of being fitted? This isn’t due to shoddy alternator design but is in fact due to shoddy mechanics not doing their job correctly.
So what are mechanics not doing correctly? Well, it all comes down to properly ensuring that the battery is fully charged. If the car battery is not charged, the alternator will fail to handle the vehicle's electrics and charge the flat battery. This is likely to result in an overloaded alternator. The rectifier will then blow and the unit will be rendered useless.

https://www.qxcomponents.co.uk/artic...ator-problems/

Yeah...I'm inclined to agree with you. Thanks for sharing! If i ever recall the source of that info, i'll be sure to pass on this info! thanks!

[john61ct]

Originally Posted by Scrimma

1 - Change alternator charging cable back to start battery.

2 - Disconnect VSR so alternator will only ever charge start battery and never the lithiums

3 - upgrade battery charger that will now only operate under my 1000w generator or shore power.

Personally I advocate all possible charge sources be available to House.

Putting all "crude" sources to the lead Starter batt, then Sterling BBs to filter those raw amps to the LFP is to me the way to go for minimum disruption.

Visualize each (LFP pack + BB charger) as a packaged unit, can feed it whatever DC charge source is available without worrying about volts or amps, the BB is the only one that directly feeds the LFP.

You can replace the BB above with an AC powered charger instead, but that is sacrificing alternator, possible solar, wind etc.

While with the BB, those options are open, can use your existing AC charger.

Key question, how often for how long are you off grid? What happens when the genny fails?

[john61ct]

Originally Posted by Scrimma

If i ever recall the source of that info, i'll be sure to pass on this info

That would be good, know to avoid FFR.

[Scrimma]

Originally Posted by john61ct

Personally I advocate all possible charge sources be available to House.

Putting all "crude" sources to the lead Starter batt, then Sterling BBs to filter those raw amps to the LFP is to me the way to go for minimum disruption.

Visualize each (LFP pack + BB charger) as a packaged unit, can feed it whatever DC charge source is available without worrying about volts or amps, the BB is the only one that directly feeds the LFP.

You can replace the BB above with an AC powered charger instead, but that is sacrificing alternator, possible solar, wind etc.

While with the BB, those options are open, can use your existing AC charger.

Key question, how often for how long are you off grid? What happens when the genny fails?

Now you've got me thinking! So BB I take it is battery to battery/dc to dc charger right? If so, then I'm starting to pick up what you're putting down and it sounds quite nice indeed.

I know nothing about BB's. Do you have a link or a reccomeneded one for my situation? And it would require a separate BB for each 200ah LFP? I assume BB's are one directional in their charging direction? (They shoot power from one to the other but not capable of shooting it back to the start battery in this case? Not that I would want it to as it's getting direct alternator charge, but a safety thing?)

I love the idea of keeping my 40A battery charger as is!

Would the BB's need to be 20A each to the LFP due to the fact my battery charger is 40A (2x20A BB's)?

Do you know of any wiring diagrams that would show this kind of setup?

I am an avid Google searcher and can but out most problems, but sometimes it's know what to ask Google that counts. Alas, this is still beyond me on this topic.
Very much appreciate the time you've taken to assist in this!

To answer your key question...my wife and I are about to move onto our 40' Dehler mono this coming weekend and plan to cruise extensively. Primarily the East coast of Australia for the first couple of years, then out into the big blue to find more adventures. That in mind, the most reliable power source is key. Generators do fail...

[Groathill]

The Yanmar Hitachi 80A alternator has a rather crude way of regulating the output voltage down when the alternator heats up while generating a high output current, this in order to protect the alternator from overheating and destruction.


When charging lead type batteries this goes fairly well as the battery's input resistance rises after a while, the temperature rises in the alternator - all in all this results in a fairly low charging current. You rarely charge with as much as 80A and after a while, it is much, much less. If you have a battery charging monitor you will see this.



With LIFE batteries it is very different; the alternator charges LIFE quite well with somewhat lower voltages and the input resistance in the LIFE is much lower - so you will charge far more efficient, but you risk overheating the Hitachi alternator and destroy it.


There are a few things you could do; for one use forced air cooling with large diameter (80 - 100mm) hose with a powerful fan taking air either from the outside or the bottom of the boat, the engine needs a lot of air for combustion anyway.


The other thing is to do a bit of surgery to the alternator and fit a good external regulator designed for charging LIFE batteries. If you are handy you could do this yourself or hire someone with knowledge.


The size of your LIFE bank also matters concerning how much you will stress your alternator. Buying and fitting a better suited alternator is another option.

[john61ct]

Sorry that wasn't clear.

https://www.sterling-power-usa.com/b...ychargers.aspx

The BB series ones are the subset that offer adjustable voltage setpoints.

Originally Posted by Scrimma

And it would require a separate BB for each 200ah LFP?

Or more than one, depends how fast you want/need to recharge. Many believe over .5C is "too fast" and will reduce longevity, even say limit to a .3C rate, 100A and 60A respectively.

Depends on the cells, BMS, wiring and of course upstream power available.

Start with two 60A for redundancy, see how you go, they're used to shipping to remote places.

> I assume BB's are one directional in their charging direction?
Yes. Since Starter needs next to nothing, that rarely needs to be the target side.

No VSR needed.



> Would the BB's need to be 20A each to the LFP due to the fact my battery charger is 40A (2x20A BB's)?

The upstream source can be 400A, but a 60A B2B will only pass 60A or less. Can derate if needed.


> Generators do fail...

Yes they do. This concept lets any old DC source feed your bank no matter how primitive.

Note Redarc, Projecta, CTEK other brands of DCDC chargers widely used by patriotic Aussies, do not allow for Sterling's user-custom voltage setpoints.

Contact Sterling for support and dealer reco. Do not buy just on price, strive to build a relationship with a dealer that will take the time to support you, or buy direct from the UK.

[john61ct]

Originally Posted by Groathill

The Yanmar Hitachi 80A alternator has a rather crude way of regulating the output voltage
…
The size of your LIFE bank also matters concerning how much you will stress your alternator.

All these issues go away by fronting the alt with an adjustable DCDC charger.

At a given ambient temperature, the alt will support up to X amps continuous output.

Derate the DCDC to below X and Bob's your uncle.

> Buying and fitting a better suited alternator is another option

Yes, if there is sufficient space for a large-frame,

ideally off-loading the diodes / electronics to a cooler location,

if the engine has enough spare horsepower available, and

fitting the right size multi-vee serpentine pulley setup

even 200+A continuous output alts are available.

Controlling output with a Balmar MC-614, can then take the current-limiting DCDC out of the picture, at least wrt that one charge source.

[jewt]

Go to PKYS INC online, they have everything you need very helpful and
knowlegable.

jewt

[john61ct]

For LFP?

I mean yes great company in general, but

afaik they only deal in Victron's proprietary packaged LFP systems

So their advice would be limited I'd think

[Scrimma]

Originally Posted by john61ct

Sorry that wasn't clear.

https://www.sterling-power-usa.com/b...ychargers.aspx

The BB series ones are the subset that offer adjustable voltage setpoints.

Or more than one, depends how fast you want/need to recharge. Many believe over .5C is "too fast" and will reduce longevity, even say limit to a .3C rate, 100A and 60A respectively.

Depends on the cells, BMS, wiring and of course upstream power available.

Start with two 60A for redundancy, see how you go, they're used to shipping to remote places.

> I assume BB's are one directional in their charging direction?
Yes. Since Starter needs next to nothing, that rarely needs to be the target side.

No VSR needed.



> Would the BB's need to be 20A each to the LFP due to the fact my battery charger is 40A (2x20A BB's)?

The upstream source can be 400A, but a 60A B2B will only pass 60A or less. Can derate if needed.


> Generators do fail...

Yes they do. This concept lets any old DC source feed your bank no matter how primitive.

Note Redarc, Projecta, CTEK other brands of DCDC chargers widely used by patriotic Aussies, do not allow for Sterling's user-custom voltage setpoints.

Contact Sterling for support and dealer reco. Do not buy just on price, strive to build a relationship with a dealer that will take the time to support you, or buy direct from the UK.

So, if I have this correct, I would need a 60A BB between my start battery and my lithium. If I am happy with 60A max charge through my alternator and start battery to my LFP, then that should be all I need? IF I wanted more power coming from a higher output alternator if I changed that out, then I would need a couple of these BB's to throw in approx 120A from the alternator? My 240v charger is only a 40A currently and I don't plan on upgrading that at this point, so all I have to worry about that is ensuring the BB that is connected after the start battery has the correct LFP charging algorithm as my 240 charger doesn't have that currently...?

I am definitely looking for the simplest and most cost effective way of doing this and so far, installing a single 60A BB seems to be it...

I assume charging the parameters of those sterling BB's is easily done through bluetooth? Or buttons on the device? Or will I be roped into buying the display module too?

[Scrimma]

Originally Posted by john61ct

All these issues go away by fronting the alt with an adjustable DCDC charger.

At a given ambient temperature, the alt will support up to X amps continuous output.

Derate the DCDC to below X and Bob's your uncle.

> Buying and fitting a better suited alternator is another option

Yes, if there is sufficient space for a large-frame,

ideally off-loading the diodes / electronics to a cooler location,

if the engine has enough spare horsepower available, and

fitting the right size multi-vee serpentine pulley setup

even 200+A continuous output alts are available.

Controlling output with a Balmar MC-614, can then take the current-limiting DCDC out of the picture, at least wrt that one charge source.

Hi and thanks for your input! I'm starting to feel like a DCDC charger with lithium charging algorithm is the way to go. I assume creating a positive and a negative bus for the LFP batteries and the connecting my DCDC charger to that after the start battery would be the best way to go? Can you recommend a good DCDC charger approx 60A-80A with lithium charging algorithm for this job?