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03-12-2019, 23:00
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#16
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Registered User
Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 5,607
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Re: AGM batteries, PSOC and sulphation
Quote:
Originally Posted by a64pilot
The question I have is, does AGM sulphate more than flooded or Gel?
Or does it nor recover as well from sulphation, or both?
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I don't know the answer to your first question. I had thought that all LA batts' sulfation rates were not dependent on type, but that could certainly be wrong. I thought the problem with AGMs -- and why they require more charging -- is more about the inability to address the sulfation because of the finite amount of electrolyte and, except for Lifeline, the inability to condition/equalize.
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03-12-2019, 23:58
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#17
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cruiser
Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,317
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Re: AGM batteries, PSOC and sulphation
Quote:
Originally Posted by Exile
With no attribution. Meaning you're likely misquoting.
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As stated, anyone who wants can look it up.
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04-12-2019, 09:32
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#18
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Senior Cruiser
Join Date: Sep 2007
Location: Enkhuizen, NL
Boat: Pearson 36-1
Posts: 755
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Re: AGM batteries, PSOC and sulphation
My Optima Series 31 Yellow Tops were drained flat three times in their life and I looked into desulfating by equalization and what works for "normal" batteries doesn't work with AGMs. That led me to buy a BatteryMinder charger that uses pulsed frequencies to desulfate an AGM.
My house bank lasted 10 years before I replaced them and the two I use on the starter/windlass bank are still going strong after 12 years.
I will soon buy Firefly batteries and see how they do.
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04-12-2019, 11:51
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#19
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Registered User
Join Date: Sep 2013
Location: Alert Bay, Vancouver Island
Boat: 35ft classic ketch/yawl.
Posts: 1,980
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Re: AGM batteries, PSOC and sulphation
I think this is a very good peace of journalism presenting a complex issue in simple clear terms. No it is not an exaustive sientific test or paper so there remaim questions. Main piont is that it highlights the need for regular 100% charge for any LA battery. I have made the point in several posts that, because of the higher absorbtion voltage allowed in FLA's the absorbtion phase is substantially faster so batteries suffer less from partial charge. I suggest that more consideration should be given to a banks absorbtion acceptance rather than bulk acceptance rate which tends to be the figure given by manufacturers. As other point out FLA's can be agressivly recharged with no damage and within reason this seams to correct som sulfation. By all means use sealed batteries for convienice but be ralistic about the cost penalties and lifespan.
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04-12-2019, 12:20
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#20
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Marine Service Provider
Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 3,197
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Re: AGM batteries, PSOC and sulphation
Quote:
Originally Posted by Exile
Show us the Northstar test while you're at it though.
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Northstar was late to submit a battery for the testing. Luckily for them the East Penn product did so poorly, compared to the others, we thought it would be fair to give it another go in case battery #1 was just a fluke. Those results (Northstar Blue+), if I recall, are in the August 2015 issue of Practical Sailor..
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04-12-2019, 12:24
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#21
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cruiser
Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,317
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Re: AGM batteries, PSOC and sulphation
Are you saying you used
Quote:
Originally Posted by George DuBose
Optima Series 31 Yellow Tops
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to comprise a House bank?
Was this back in the day before their creator Enersys/Odyssey sold the line off to Johnson/JCI ?
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04-12-2019, 12:33
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#22
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Registered User
Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 5,607
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Re: AGM batteries, PSOC and sulphation
Quote:
Originally Posted by Maine Sail
Northstar was late to submit a battery for the testing. Luckily for them the East Penn product did so poorly, compared to the others, we thought it would be fair to give it another go in case battery #1 was just a fluke. Those results (Northstar Blue+), if I recall, are in the August 2015 issue of Practical Sailor..
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OK thanks. The May 2015 article cited in the first post did mention they would be testing the Northstar in the future so good to have a reference.
The two main issues that seem to have come up in this particular thread are
(1) whether AGMs actually sulfate/lose capacity faster than flooded (except maybe Firefly), or whether it's more a function of not being able to condition them (except Lifeline).
(2) whether Lifeline's unique ability to condition/equalize makes it a better value for a cruising boat over other AGMs.
It's all too easy for discussions to go astray in many of these battery threads these days so I thought I'd try and narrow it down. Should you be inclined to weigh in that is.
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04-12-2019, 18:04
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#23
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: AGM batteries, PSOC and sulphation
We sort of got off track being concerned about Northstar.
Yes, all lead acid batteries sulphate, I’d guess it’s probably the biggest reason they “Die”
But is an AGM more prone to sulphation than other types of LA batteries?
Do AGM’s lose capacity faster in a PSOC situation than a regular flooded LA battery?
Then I guess the graduate question is, which battery chemistry loses the least capacity or has a lower rate of loss than others, or is there any difference?
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04-12-2019, 18:28
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#24
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Registered User
Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 5,607
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Re: AGM batteries, PSOC and sulphation
As Roland pointed out above, there doesn't seem to be much question that the answer to your last question is that, speaking generally of course, AGM’s lose capacity faster in a PSOC situation than a regular flooded LA battery. That's the consensus as I understand it anyway. The only reason I've stuck with them thus far is (a) they're all (800+ah nominal) directly under the main berth where I usually sleep and I'm (sorta) concerned about out-gassing, and (b) the boat has thus far mostly been connected to shore power. When I start cruising in earnest I might very well go to flooded, or maybe Firefly's. All my batts are reasonably accessible so the watering part doesn't bother me.
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04-12-2019, 18:52
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#25
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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Re: AGM batteries, PSOC and sulphation
I’m not disagreeing that they are more susceptible and or less tolerant to sulphation, or at least PSOC use.
But is there any testing data to substantiate that?
And, if there has been testing did it find a chemistry that is less susceptible than the others?
I think my next bank will be Gel, just based on Maine Sails comments and others that if they are well cared for and properly charged a decade isn’t unreasonable.
Now, as it’s my unsubstantiated belief that sulphation is most often what causes a batteries Retirement, then it would seem to reason that Gels are less susceptible?
Somebody has to have tested for this, Sandia national labs or other agency?
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04-12-2019, 21:22
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#26
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cruiser
Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,317
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Re: AGM batteries, PSOC and sulphation
Pretty sure we would have come across such studies by now if they existed.
LFP is the real answer to your question.
GEL also does not have the general "more robust" advantages of quality FLA, cannot tolerate inaccurate voltage regulation or high current rates, IOW only gives long lifespans when well and truly coddled.
Which is why such a tiny percentage of installs these days for this use case.
If you really want top notch reliability for over a decade without precise coddling, go Rolls / Surrette or equivalent if any.
But of course abusive conditions will destroy any value proposition based on long-term ROI.
In which case Deka GC2s at $1 per 12V Ah can't be beat, just replace as needed and invest the savings elsewhere.
Quote:
Originally Posted by Exile
OK thanks. The May 2015 article cited in the first post did mention they would be testing the Northstar in the future so good to have a reference.
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AFAIK MS did the testing and wrote all the articles/posts discussed here, so not sure to whom "they" is supposed to be referring?
He has already determined that Lifeline's ability to equalize did not overcome Odyssey and Northstar's superior resistance to PSOC conditions.
Not to say they aren't excellent, even "the best AGM" otherwise, just less excellent in **this one** aspect, sulfation **due to PSOC abuse** .
But IMO that should be less and less of a factor these days,
the old "most sailors just can't" regularly get to 100% SoC just no longer being true
for those with decent solar **plus an ICE source(s) conveniently available**,
making the primary question here pretty moot in those cases.
Assuming that is, you've calibrated your sources' stop-charging point against measured endAmps, in order to avoid "premature infloatulation".
Failing that is IMO a **much** more common cause of PSOC murdering banks, as it happens most of the time, even for boats with regular access to plenty of available energy.
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04-12-2019, 23:22
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#27
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Registered User
Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 5,607
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Re: AGM batteries, PSOC and sulphation
Anyone else notice that these battery/electrical threads no longer seem to attract the expertise they used to?
[sigh]
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05-12-2019, 12:07
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#28
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Registered User
Join Date: Jul 2005
Location: Bellingham
Boat: Outbound 44
Posts: 9,319
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Re: AGM batteries, PSOC and sulphation
Quote:
Originally Posted by Exile
Anyone else notice that these battery/electrical threads no longer seem to attract the expertise they used to?
[sigh]
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Sigh indeed. The same repeated volume gets old.
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05-12-2019, 12:42
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#29
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Registered User
Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 5,607
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Re: AGM batteries, PSOC and sulphation
Quote:
Originally Posted by Paul L
Sigh indeed. The same repeated volume gets old.
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To say nothing of potentially costly & frustrating if taken as the gospel it's being presented as. Too many variables and too much anecdotal information to generalize so much, as Maine Sail himself cautions in one of his comments to the PS article cited by the OP.
John Harries on the Morgan's Cloud website has an extensive analysis of destroying his Lifeline's in only one year, but then learning better practices and having another set last a more typical duration. But what's "typical?" As I recall, SailingLegend (an EE who unfortunately no longer posts) got something like 15 years out of his Lifelines living on the hook. He said he thought they were dying after 9 (or so) but figured out how to get much more. But if there's definitive evidence that Lifeline's unique ability to be equalized doesn't make up for their tendency to sulfate more than a couple of their direct competitors, I would be all ears. But I don't think even Maine Sail would proffer that conclusion after only two tests. Maybe there's more testing & evidence out there? If so, then we certainly haven't seen it properly cited in this thread. Only the usual highly generalized, conclusory, barely decipherable copy & paste.
I fear it's driven off the familiar CF "brain trust" I've benefitted so much from since joining.
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05-12-2019, 13:34
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#30
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Moderator Emeritus
Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
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AGM batteries, PSOC and sulphation
From a private conversation that I had with I believe Justin Godber at Concorde, I was told to expect 5 years out of my bank if I fully 100% charged them twice a week and mostly got there the other five days, if I condition charged then monthly. Conditioning is what Lifeline calls what is otherwise known as equalizing.
That plan was based on making water twice a week, which for me means running a generator, and that of course would get me to 100%.
That was a pre cruising plan.
Since then I’ve discovered it’s not hard for me to get them to 100% charged every day with a 30 min generator run in the morning, in Winter in the Bahamas.
I have seen significant recovery from a Conditioning charge, what I have is dual amp counting battery monitors one Magnum and now one Outback. Both are needed to ensure both charge sources drop to float when my acceptance at absorption voltage hits .5% of rated capacity.
Anyway I have the amp counters set for my bank being a 630AH bank, when in the morning I wake up and the Smart Gauge indicates a percent SOC that is 5% or more less than the amp counters I do a Conditioning charge, late in the afternoon when my bank is 100% charged, I don’t let it rest, cause on the hook, I can’t.
I base that on the assumption that the Smart Gauge is the correct SOC, the amp counters are a calculated number and not actual SOC.
This year I won’t be surprised if I have to set the amp counters to 600 AH, assuming I will have lost 10% capacity over the last four years.
It’s a 660 AH bank
I have had two serious events to the bank, once when new I set the charger to condition voltage and left, and came back five days later to find it still at Conditioning voltage. The bank was room temp and was accepting I think .2 amp charge, but it couldn’t have been good for it.
Then I came back to the boat one weekend to find the marina’s pedestal circuit breaker had failed and my bank had run down until it was below the fridges operating voltage. That also couldn’t have been good for it, but since cruising I can watch it every day of course and we have had no such events.
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