AGM batteries, PSOC and sulphation

[StuM]

Originally Posted by Exile

You may or may not be correct, but it's not clear to me from Maine Sail's description of the latest Sterling model or the wiring diagrams he provides that the charge source can be anything other than a battery bank. This source battery bank can itself be charged by a number of different sources, including obviously an alternator, but it's not clear the alternator can be wired directly to the B2B.

Where are you seeing that this is possible?

Are you saying that it won't work if you interrupt the circuit to the house bank?


Why?

[Exile]

Originally Posted by john61ct

I never said anything about wiring anything to the alternator.

I thought you had, starting with this comment:

Maybe it was your choice of wording, but putting a B2B or DC-DC charger "in front of the bank input" suggests it could be used between a charge source and the battery banks. But now that I've gone back and read it more carefully I understand what it means even less.

The input to a DCDC can be anywhere along a low-resistance location - fat wire, tight clean connections - on the source **circuit** side.

Sterling just recommends the posts of the Starter batt, if the engine circuit is source, since that battery makes a good buffer to absorb any spikes / surges etc.

It is just a basic knowledge of how this stuff works, the Starter battery is at a lower voltage than the circuit with the alt going,

I don't think I suffer from a lack of basic knowledge of how its works, but only because I've read clearly worded explanations from actual experts and/or those actually familiar with such devices from actual usage. By contrast, I often have difficulty understanding what you are trying to explain.

same with a solar charger, a mains charger being live if the engine or alt is turned off,

no current can flow out of the Starter battery, current only flows from a higher voltage to lower, laws of physics.

I'm really not sure how else to get it through to you if you don't understand, the energy does not flow from any battery, but from the actual charge sources that are active on the input side.

My question never had anything to do with these elemental concepts. Stick to the specific question presented and not a Level 101 lecture.

Just as, on the target side (House in this case), if there are House Loads drawing higher current than what the DCDC is supplying, no energy will flow into the House bank, but out of that bank, as it feeds those loads together with the DCDC unit.

If by "this case" you mean the wiring diagram I attached above, the House bank is the source bank and the starter or bow thruster battery is the target bank. Read the definitional section of the article.

No battery is ever the actual source in charging another battery.

I think what you mean is that no battery is ever the actual charging source, but it can be the source bank for charging a target bank. Your posts would be clearer if you used the common terminology.

Yes it is possible to configure a DC-DC charger to do so - with no actual charging sources active - but that would be foolish and is never done in practice.

Not the issue, not being questioned, and not debatable.

[Exile]

Originally Posted by StuM

Are you saying that it won't work if you interrupt the circuit to the house bank?


Why?

By "charge source" I meant the battery bank which inputs into the B2B to charge the target bank, not what is supplying the power.

[john61ct]

Originally Posted by Exile

By "charge source" I meant the battery bank which inputs into the B2B to charge the target bank, not what is supplying the power.

It is that which "is supplying the power" that "inputs into the B2B".

Visualize all charge sources, wind, hydro, fuels cell, mains, alt, genset, solar, whatever, on one side.

Target bank on the other.

Put the LFP bank in a case with the DCDC, and you can charge it from any boat, car, truck, etc.

By "put a DCDC charger in front of the bank input" I mean that it goes between the two, to ensure the bank gets what's good for it, no need to replace or alter any of those sources.

[john61ct]

> the House bank is the source bank and the starter or bow thruster battery is the target bank.

The latter is accurate, but the "source bank" is more accurately described as "the bank on the source circuit".

In fact I think you do now understand the distinction. In practice it does not really matter, so not much point in arguing the semantics.

Originally Posted by Exile

My question never had anything to do with these elemental concepts. Stick to the specific question presented and not a Level 101 lecture.

But it has been indeed that very lack of understanding of such fundamentals that has caused you this confusion.

As a practical matter I believe you now understand the issues involved.

[john61ct]

Found on a reseller site:

"The BB1230 will boost the voltage to the batteries if input voltage is too low & reduce the voltage if the supply current is to high ensuring the optimal charging current is maintained at the batteries.

The BB1230 is fully compatible with the latest EURO 5/6 Regenerative Braking Systems and smart charging alternators where a standard split charge relay does not suffice.

Compatible with Mercedes Benz Blue efficiency, VW Blue Motion, Ford Econetic and Vauxhall Ecoflex systems amongst others

Multiple Activation Modes

Automatic for most non vehicle applications

Manual for remote activation.

Regenerative braking (requiring ignition feed),

Automatic regenerative braking, requiring no ignition feed.

The Current is NOT taken from the input battery and given to the output battery.

The B2B uses alternator power to charge the output battery.

Manual mode and regenerative braking mode allows you to override this."

(added emphasis mine)

[Exile]

Originally Posted by john61ct

> the House bank is the source bank and the starter or bow thruster battery is the target bank.

The latter is accurate, but the "source bank" is more accurately described as "the bank on the source circuit".

In fact I think you do now understand the distinction. In practice it does not really matter, so not much point in arguing the semantics.

But it has been indeed that very lack of understanding of such fundamentals that has caused you this confusion.

As a practical matter I believe you now understand the issues involved.

As a practical matter, and the only matter I was asking about, a B2B/DC-DC device is not the appropriate one to provide 3-stage external regulation for my internally regulated alternators. My confusion derived from reading lengthy posts of yours that use inaccurate terminology and confusing grammar. It's a disservice to others to try and proffer clear advice that you haven't yet clarified in your own mind. Your many deviations & abstractions only exacerbate the confusion.

[Exile]

Originally Posted by john61ct

Found on a reseller site:

"The BB1230 will boost the voltage to the batteries if input voltage is too low & reduce the voltage if the supply current is to high ensuring the optimal charging current is maintained at the batteries.

The BB1230 is fully compatible with the latest EURO 5/6 Regenerative Braking Systems and smart charging alternators where a standard split charge relay does not suffice.

Compatible with Mercedes Benz Blue efficiency, VW Blue Motion, Ford Econetic and Vauxhall Ecoflex systems amongst others

Multiple Activation Modes*-

Automatic for most non vehicle applications

Manual for remote activation.

Regenerative braking (requiring ignition feed),

Automatic regenerative braking, requiring no ignition feed.

The Current is NOT taken from the input battery and given to the output battery.* The B2B uses alternator power to charge the output battery.* Manual mode and regenerative braking mode allows you to override this."

Relevance? Why are you copying & pasting this? Which reseller site?

[john61ct]

Sorry, added bolding to the relevant section.

GIYF

[john61ct]

Originally Posted by Exile

As a practical matter, and the only matter I was asking about, a B2B/DC-DC device is not the appropriate one to provide 3-stage external regulation for my internally regulated alternators.

In practice you are wrong, it can indeed perform that function just fine, but it may not do so better than other alternatives for **your** use case.

Technically you are correct, it is strictly speaking not a DCDC's job to "regulate an alternator".

It only regulates **its output**, on the way to the target circuit and bank(s) on the output side.

It does not affect the alternator's output **on the source circuit** nor how batteries on that side are charged.

But note how you phrased your question, which got this whole tangent started

Originally Posted by Exile

Which battery-to-battery charger did you have in mind that can use an alternator as a charge source?

To which I gave a long list which do precisely that. Sterling just happened to be at the top of that list, everything we discussed applies equally well to the rest as well.

[Pete7]

Originally Posted by StuM

Are you saying that it won't work if you interrupt the circuit to the house bank? Why?

Am I missing something here because I don't understand that diagram that Excile posted or Stu modified. Ignoring the shorepower and solar bits, why is the alternator connected directly to the house bank?

Surely the B2B product is being used in the wrong place here? who cares what the engine start battery is getting, its the house bank that you want to molly cuddle because that's were the money is. I think the wrong devices are being used. Surely the alternator should be connected to the engine start battery and if you want to control the charging profile then use one of these:

https://cdn.shopify.com/s/files/1/06...s/A2Bs.pdf?743

Or the alternator regulator:

https://sterling-power.com/collectio...-bw-waterproof

Then to charge the house bank which may be a different battery type (and I am trying not to mention exotic types ) use a battery to battery charger:

https://sterling-power.com/collectio...rip-proof-ip21

Image from Sterlings B2B charger manual:

[Pete7]

Originally Posted by john61ct

SoH is indeed best measured with precisely timed CC load tests.

It is not hard to be able to do so accurately and regularly yourself.

A rougher estimate can be done more easily using an Ah meter and a few light bulbs.

But yes, all such specialized procedures much easier on shore power, also commissioning / breaking in a new bank, proper equalizing / capacity restore conditioning, etc.

Do you honestly believe that yachties fit new batteries then after breaking them in separate the batteries out and individually test the capacity of each battery which will probably need to be done one at a time

Ignoring the 11% with LFP, which due to the high purchase price might be monitored to protect their investment and they likely have the knowledge and skills required. I put it to you that this is all purely theoretical. In the real world it just doesn't happen with SLA or FLAs on the majority of boats. Walk some docks and ask yacht owners if they do this to new batteries, because I know the answer you will get back.

Knowledge of the theory is all well and good, but life on board isn't like that as I am sure you will learn when you buy a boat.

John, I hope this helps explains the difference between what is written in a book or manufactures leaflet and what really happens on the water.

__________________________________________________

If I was to offer advice to someone buying new batteries for a boat I may suggest the following:

1. On receipt or in the shop, inspect carefully for any damage.

2. check the date of manufacture (DOM). For Rolls batteries this is easy as they stamp the date on the top in clear letters. For Trojan a bit more difficult, but a code is stamped in the lead battery terminal which you need to look up.

3. With a simple 12v battery monitor check the voltage.

If damaged, or the date is getting on a bit, or the voltage is low, then reject in favour of newer batteries. You really don't want to lug them down to the boat, fit, toss out the old ones and then wonder if they should be returned, a huge faff.

I rejected the last set of Rolls I ordered doing this as the DOM was unacceptable the voltage down to 50%.

Pete

[Maine Sail]

Originally Posted by Exile

but it's not clear the alternator can be wired directly to the B2B.

Just to be clear, the current Sterling B2B’s need a battery bank connected on both the input and output sides. You cannot connect one directly to a charge source. Charles is working on an optional device that will allow a quasi-direct connection to a charge source, without a battery on the input, but so far we don’t even have a prototype...

[Maine Sail]

Originally Posted by Exile

It's a very simple question. Can an alternator be used as the charge source for a battery-to-battery charger as you've claimed? Or a **DCDC** charger if you prefer. A simple yes, no, or "I don't know" would do nicely at this point.

Originally Posted by john61ct

I have answered so many times!

Yes!

John,

Care to reconsider your factually stated yet 100% inaccurate
statement......?


.

[sailorboy1]

I take it the original subject is over