Any two years reviews for Firefly batteries?

[john61ct]

Say a particular bank, super coddled including shallower DoD cycling on average might last 9 years.

An identical setup, just more frequently deeper cycled, "only" lasts 7 years.

While an owner drawing down every day to say 80% may "only" get 2-3 years.

These numbers are just examples, to illustrate the principle I stated, personally I think probably overly optimistic if using 70-80% SoH as EoL, but specific numbers are not the point, no one knows until decades after widely used in the field, and too many variables to pin down anyway.

My point is the above **relative** cause and effect is inherent in the battery chemistry.

Firefly is revolutionary in how well it stands up to deeper cycling - meaning the lifetime curve is not **as steep** as the rest.

And especially wrt to resisting PSOC, which is harder for many owners to avoid.

But their unique flavour of AGM does not upend the laws of chemistry and physics.

Lab results have nothing to do with Real Life's actual numbers, but contact Bruce you can likely get a DoD vs cycle lifetime chart that confirms all this.

[Delfin]

Originally Posted by Trackskinz

And on a related note, long story but my alternator does not have an actual regulator (adjustable rheostat type device) on my 55 amp alternator. Would something like a Balmar be configured to work with what amounts to an automotive alternator? The one that is supposed to be used with my alternator only puts out 13.6V.

The Balmar is a regulator, so if you set your rheostat as high as it will go, the 612 will step through the charge cycle however you've programmed it. This assumes Max output of the rheostat is 15 volts or more, which it should be. Perchance, is it a Spa brand? Since you've already removed the automotive regulator, you can just install the Balmar.

[Delfin]

Originally Posted by jkleins

What evidence do you have for this? I routinely drop mine below your “recommended” levels without any sign of decreased capacity as do many on this forum that have Fireflys. Do you have any reports that corroborate this? If you do please publish them as they would be interesting to see and add new information to the what is currently available.

Jim

Don't hold your breath...

[jkleins]

Originally Posted by john61ct

Say a particular bank, super coddled including shallower DoD cycling on average might last 9 years.

An identical setup, just more frequently deeper cycled, "only" lasts 7 years.

While an owner drawing down every day to say 80% may "only" get 2-3 years.

These numbers are just examples, to illustrate the principle I stated, personally I think probably overly optimistic if using 70-80% SoH as EoL, but specific numbers are not the point, no one knows until decades after widely used in the field, and too many variables to pin down anyway.

My point is the above **relative** cause and effect is inherent in the battery chemistry.

Firefly is revolutionary in how well it stands up to deeper cycling - meaning the lifetime curve is not **as steep** as the rest.

And especially wrt to resisting PSOC, which is harder for many owners to avoid.

But their unique flavour of AGM does not upend the laws of chemistry and physics.

Lab results have nothing to do with Real Life's actual numbers, but contact Bruce you can likely get a DoD vs cycle lifetime chart that confirms all this.

So in other words you just made it up.

I routinely discharge mine to around 70-80% and have been going good for three years. I know of no one else who has had the steep or “major” drop off in capacity that you mentioned in your first post. In fact the exact opposite is true. Most of the posters here aren’t seeing a capacity fall off. Please don’t just make crap up. You often post useful information but knowing now that it is just coming off the top of your head or from extrapolation of some belief about “battery chemistry” it all seems suspect.

Jim

[john61ct]

I know for sure, even if you end up getting 15 years lifetime before hitting whatever SoH% you have defined as your EoL,

You would have gotten lots **more** only going to 50%, and even more than that at 20% DoD.

It is just obvious and common sense knowing how batteries work.

The same is true for LFP by the way.

I am not saying that going to 80% DoD is bad practice, of course do whatever you like with your bank, many people work like that in weight-critical use cases.

Just don't kid yourself doing so has zero impact on longevity.

Are you actually doing standard load tests on your bank against a commissioning benchmark? If not, then how would you even know their current SoH? you certainly can't just tell "intuitively", many just kee going until the bank stops working.

Three years is not a long time.

Maybe the new Balmar SG200 could tell you now, but IMO too early to tell how that does with Firefly specifically.

[FlyingScot]

Originally Posted by jkleins

So in other words you just made it up.

I routinely discharge mine to around 70-80% and have been going good for three years. I know of no one else who has had the steep or “major” drop off in capacity that you mentioned in your first post. In fact the exact opposite is true. Most of the posters here aren’t seeing a capacity fall off. Please don’t just make crap up. You often post useful information but knowing now that it is just coming off the top of your head or from extrapolation of some belief about “battery chemistry” it all seems suspect.

Jim

If anyone is making things up, it is people who think DOD has no effect on life.

Every lead battery I've ever seen has either not published any data or shown that larger DOD = less cycle life. If you have data to show otherwise, we would all like to see it.

Standard G31 published specs for FF Oasis:
50% DOD ~3600 cycles
80% DOD ~1000 cycles

L15+ 4v published specs:
50% DOD ~4900 cycles
80% DOD ~1475 cycles

Clearly Firefly thinks deeper discharges shortens the expected life. Some quick math shows HUGE REDUCTIONS IN EXPECTED LIFE!

https://www.bruceschwab.com/advanced...asis-group-31/

So have you capacity tested your battery? Did you do before and you can share the previous data too?

[john61ct]

Thanks, not as if my "claims" were extraordinary.
As I said

Originally Posted by john61ct

But their unique flavour of AGM does not upend the laws of chemistry and physics.

Lab results have nothing to do with Real Life's actual numbers, but contact Bruce you can likely get a DoD vs cycle lifetime chart that confirms all this.

[admiralslater]

Here is something else to argue over, in an earlier post I talk about crashing my FF bank . It went down to 4 or so volts if I remember correctly. It stayed there for several weeks . It had some solar going in from pannels that where under a sun shade so amost nothing .
The question is is that one long cycle or did the minute solar imput change it to multiple. And what does the forum think will happen in the long run

[Jim Cate]

And what does the forum think will happen in the long run

Who cares what the forum thinks? I'd like to know what REALLY happens, and I bet that the rest of the forum would too!

Jim

[john61ct]

The question about one cycle or many is not significant.

Resistance to ordinary mistreatment is one thing, but no one claims FF are invulnerable to disaster events.

I am sure at best some number / percentage of lifetime cycles were lost off the back end, that would be true even sitting around 10V for a few hours.

Very likely the affected batteries' current performance were affected enough to use the term "damaged".

Ideally a precise standard load / capacity test could be conducted before and after the event on the impacted batts, or perhaps between them vs control units in the bank.

Otherwise such vague statements will have to do, limited data can't yield precise numbers, basically comes down to "good enough to keep using" vs "needs replacing".

A load test will not be needed if gross differences in performance show up in normal cycling.

[admiralslater]

Originally Posted by Jim Cate

Who cares what the forum thinks? I'd like to know what REALLY happens, and I bet that the rest of the forum would too!

Jim

I was asking if a long term discharge is one cycle, I know that some portion of the life span is removed.

[admiralslater]

Sort of a “ place your bets” question

[jack630]

I just ran across this thread and thought I'd put my data point in. I installed 8 FF's on our boat in the spring of 2017, one for the starter and 7 for the house. Previously, we had 2 8D and 1 4D (starter) that died after 2 seasons. When I installed the FF's I replaced the two isolators with ACR's. I replaced two smaller alternators for one 215 Amp alternator that I typically run at 75%. I have a Balmar Smartguage. We don't have solar or generator or inverter at this point. With this system, we spent 2 months in 2017 and 3 months in 2018 traveling the Great Lakes and I absolutely love it. We plan to move onto the boat full time next year.

Over night on the hook, the batteries are down to 80-90%, after 2 nights 60-70% and 3 nights 40-50%. I don't have the exact time with respect to SOC but several hours of motoring will bring the batteries up to full charge. On the rare occasion that we get into a marina, the 60 amp charger probably takes a good 8 hours or more to charge the batteries.

So far, the FF's are functioning as advertised. The added benefit is 1) I can handle a Group 31 battery but not an 8D, 2) I don't have to keep checking the water level in the battery and 3) I don't have to worry about sulfuric acid sloshing about in the boat and 4) compared with other AGM's, I don't have to worry about having a 100% charge every night.

[jkleins]

Originally Posted by FlyingScot

If anyone is making things up, it is people who think DOD has no effect on life.



Every lead battery I've ever seen has either not published any data or shown that larger DOD = less cycle life. If you have data to show otherwise, we would all like to see it.



Standard G31 published specs for FF Oasis:

50% DOD ~3600 cycles

80% DOD ~1000 cycles



L15+ 4v published specs:

50% DOD ~4900 cycles

80% DOD ~1475 cycles



Clearly Firefly thinks deeper discharges shortens the expected life. Some quick math shows HUGE REDUCTIONS IN EXPECTED LIFE!



https://www.bruceschwab.com/advanced...asis-group-31/



So have you capacity tested your battery? Did you do before and you can share the previous data too?

Thank you for providing the evidence I was asking about. I never argued that john was wrong just that he was saying things he was unable to back up with any evidence which I believe you should not do if you are holding yourself as an “expert” as he does.

You clearly have some evidence to back up john’s claim and I am sure he appreciates your help. I will have to disagree with your characterization of the decrease in cycle life as “HUGE” but that type of opinion certainly would not be something that I would argue about with the numbers you cite so thank you for your contribution.

Since I have not come close to 1000 cycles I may not be seeing the decrease in life that is predicated. Or maybe it occurs more suddenly then I am expecting (although that doesn’t seem to fit with anything others are reporting).

But either way thank you for providing references for your statements. It would be nice if everyone did who makes broad claims like this. It would make the forum much more useful and less about personality.

Jim

[Delfin]

Originally Posted by jkleins

But either way thank you for providing references for your statements. It would be nice if everyone did who makes broad claims like this. It would make the forum much more useful and less about personality.

Jim

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