AGM batteries, PSOC and sulphation

[sailinglegend]

Originally Posted by sailorboy1

So Lifeline says that AGMs DO suffer more from partial recharges.

This is one of the reasons I haven't posted for a long time. Please put your glasses back on.

What Lifeline say is ALL batteries suffer from partial recharges.

[sailorboy1]

Originally Posted by sailinglegend

This is one of the reasons I haven't posted for a long time. Please put your glasses back on.

What Lifeline say is ALL batteries suffer fro partial recharges.

YOUR post #83 paragraph 2

[sailorboy1]

Besides I believe everyone accepts that all batteries suffer. If that was all that long post based on the Lifeline guy said ......... thanks

[Maine Sail]

Originally Posted by Dockhead

But even your info is not entirely up to date -- Charles has been shipping DC-DC chargers made for direct connection to the alternator for several years already, at least over here in Europe:

https://sterling-power.com/collectio...ttery-chargers

That's an entirely different product than was being discussed, and one specifically designed to not need a battery on the input side. We sell the Sterling A2B's here too, have been for many years, but it is called and an A2B or Alternator to Battery charger not a Battery to Battery Charger.

The device Charles is working on, perhaps already shipping in Europe just not here, will allow a Sterling B2B to be quasi-directly connected to an alternator. Why? The B2B's have more features for LFP than do the A2B products..

[sailinglegend]

Originally Posted by sailorboy1

YOUR post #83 paragraph 2

I have to correct you again!

That was a quote from a64pilot - not from me. This is what started this whole thread.

It glasses time again, but please read this thread from the beginning.

[a64pilot]

You guys really don’t think for instance your going to call say Island Packet to use my boat do I don’t offend and expect them to start talking about poor performance to windward and it not being as fast in light winds are you?
No of course not, they are going to stress the strengths of their product and either gloss over or ignore the weaknesses, and not because they are trying to be shady or anything, they build a good product that they are proud of.
It doesn’t make it a bad boat or product either, it just means that the perfect boat or product doesn’t exist.

So if you want to know about the weaknesses of an Island Packet, don’t call the factory and speak to an owner of the plant.

[Tx J]

Interesting thread lots of good info, going to try to add a bit to it about an as yet unmentioned AGM (and many other types) battery producer for many applications: Leoch.

Their particular battery series/model I'm using in another vehicle could have a marine use.
Mine are the deep-cycle, AGM VRLA, LPC12-100 (12V100AH), in a series string of nominal 48V. The LPC12-100 is basically a G-31 size (available with different terminal types), and also as 75Ah & 140Ah capacities. Other batt series come in many formfactors/sizes.
The 75&100Ah batts should be readily available at the home supply store whose initials are "HD". Last time I looked the LPC12-100 (~G-31) were about $225/each. Might be an alternate batt for marine use; and there are HDs all over (may have to 'special order' them).

I mention them partly because of their useful extensive, detailed, freely available battery data, some of which I'll post below. [disclaimer: I have no ties, simply have been using them and am impressed, so far]

The usage in which I'm now using these batteries is (don't get excited, it's a tough application) aboard an electric lawn tractor, the Ryobi 48V/100Ah (only from HD). I have a brush country place with hellacious vegetation. This EV tractor just chews it all up, with no fuels, oil, filters, belts, heat or fumes, etc., and I baby the batts. A great machine, so far (if you look it up, in the HD customer q&a/reviews, there are some yahoos who beat their batts to an early, expensive death by doing all the 'worst practices' x10, then wonder why they have a problem-- about a boatbuck for a set of 4). Simple check: the SoC/DoD meter is not a gas tank gauge- you cannot 'run it near dry' without slaying your batts.

Back to 'general' AGM data and use, here are some Leoch LPC12-100 data sheets which may help here a little. The graph shows how DoD (and I assume to a degree, PSOC) affects longevity and SoH. The Leoch battery manual also gives pretty good charging data, I'll attach/upload it (pdf) in a second comment.
The Leoch website is http://www.leoch.us

The Leoch website lists many batteries of different types, some may be suitable for marine use and worth looking into by y'all. Don't know if they have any LFPs (been a while since I looked there), but they differentiate types and specs to a very detailed level for many applications.
Whether they are top-shelf batts I'm working on finding out. Would then consider putting a bank on the boat.

[Exile]

Dockhead -- I think the protracted thread drift & confusion between what Maine Sail properly refers to as B2B and A2B chargers was a problem with my understanding of John61's use of terminology and perhaps grammar. I tried to clarify the distinction in post #50 but MS thankfully drove it home in just a couple of sentences.

The issue was raised after another poster asked about the much discussed problem of using internally regulated alternators to charge deep cycle batteries while using the engine. This turned into a discussion of whether a B2B could be used for this purpose, or whether an A2B was the better choice for those (like me) who want to avoid the difficulty & expense of wiring external regulators into their alternators.

Sorry for whatever I may have contributed to the confusion & drift.

[a64pilot]

Originally Posted by Exile

Sorry for whatever I may have contributed to the confusion & drift.

Threads drift, and that’s fine. Often the drifting brings up things pertinent to the thread, but not originally thought about, plus drifting can keep a thread alive until it returns to its original intent, and often threads drift when the original question has either been beaten to death or it becomes pretty plain there is no answer.

However maybe say for example an electric thread ought not drift to what resin is best to prevent osmosis or completely unrelated thing.

Of course this is just my opinion, but I think sometimes we loose sight of the fact that this is a chat room, whose primary function is to learn something and maybe even be entertained a little.

[Tx J]

Here's the whole Leoch LPC12-100 AGM "Installation & Operation Guide ". Check the Leoch website for many other batteries and info: Home

[sailorboy1]

Originally Posted by sailinglegend

I have to correct you again!

That was a quote from a64pilot - not from me. This is what started this whole thread.

It glasses time again, but please read this thread from the beginning.

Post #83 on my screen was definitely from you

But I know the answer as posted by you quoting Lifeline regarding partial charges and AGMs “that’s their Achilles heel”. I doubt an AGM would ever say it more plain as that would work against them.

Meanwhile I have a new understanding of your abscess in posting.

I don’t have AGM batteries or skin in this roundabout thread. I just was interested in the answer.

[Exile]

Originally Posted by a64pilot

Threads drift, and that’s fine. Often the drifting brings up things pertinent to the thread, but not originally thought about, plus drifting can keep a thread alive until it returns to its original intent, and often threads drift when the original question has either been beaten to death or it becomes pretty plain there is no answer.

However maybe say for example an electric thread ought not drift to what resin is best to prevent osmosis or completely unrelated thing.

Of course this is just my opinion, but I think sometimes we loose sight of the fact that this is a chat room, whose primary function is to learn something and maybe even be entertained a little.

All true. There is much value to thread drift, within reason of course. Oftentimes people read tangential posts which remind them of issues or questions they've long had about their own boats but didn't think were worth starting a new thread over.

The difference perhaps with more technical topics -- maybe more so with electrical than others -- is the disparity of expertise and thus misconceptions amongst posters that SailingLegend, for e.g., is pointing out. To that end, it's all too easy for the imprecise use of terminology to mislead and then frustrate. Then there are all the variables created by individual boat systems, and the resulting difficulty of trying to apply someone's theoretical and thus generalized knowledge to specific applications. The use of absolutist language best reserved to actual experts only compounds the frustration and can waste a lot of time.

I probably fall into the category of a more typical boatowner with a little bit of knowledge who's reasonably proficient at taking care of his own boat, but is always looking for ways to learn & improve. But my lack of expert credentials & higher level proficiency motivates me to welcome corrections when I become confused or misspeak. That's the value and reward that CF has always provided. I hope it continues to attract those with valuable advice to offer.

[john61ct]

Originally Posted by Dockhead

As anyone who has even read the Sterling catalogue would know, saving several pages of pointless argument and misinformation

At no point did anyone mention connecting any DCDC charger directly to an alternator's output terminals.

Nor even connecting to the engine starter / alt circuit without a battery present to provide buffering against spikes and surges.

And Sterling's specialist A2B units, while fine for that specific use case, are not comparable to his B2B units, nor DCDC chargers in general

[john61ct]

Originally Posted by sailorboy1

So Lifeline says that AGMs DO suffer more from partial recharges.

Sorry, I must have missed that.

Could you quote or link to it?

I'm not disputing the fact that it may very well be true, in fact I feel certain that it is,

but I am very surprised that such a categorical statement was put out by a leading AGM maker.

[john61ct]

I find is bizarre that saying "X is the charge source" on a circuit

could be interpreted as meaning any given load is "connected directly" to that source's output terminals.

The misconception I was correcting, was that the current flow being modified by DCDC chargers, was coming from any battery on the source circuit.

So far, afaics not a single statement I have posted here has been shown to be false.

I would of course be grateful to be corrected, but please don't put words in my mouth just to create a straw man to knock down.

I do strive for clear and precise communication, but of course both parties' participation must be accurate in order for that to be successful.