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Old 05-22-2016, 09:08 PM   #21
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After reading about these on a marine electronics review site I thought they might make sense at $426 but with the recent price increase to $486....forgetaboutit.
Just too expensive for me.

Love the video review though!

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Old 05-23-2016, 01:37 AM   #22
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I dumped my dual 8Ds for 4 31s! I acquired 4 of the sams brand AGMs. Love them! 150 ish each two years ago. 165 now. Two of the AGMs in parallel will crank my 3208s faster than two 8Ds. The sams brand is actually made by deka.
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Old 05-23-2016, 06:52 AM   #23
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The carbon foam batteries look interesting, but I wonder about a few things.

AGMs and other lead acid batteries can be deeply discharged too. The life of the battery is determined by the number of amp-hours you run through it. The more deeply you cycle it, the fewer cycles you get, and it's nearly linear as long as you stay away from the extremes of the DOD range. There really is nothing magic about the 50% DOD limit that we tend to follow. You can run AGMs to 80% DOD on a regular basis and you will just get fewer cycles than at 50% DOD. Or you can run to only 20% DOD and get more cycles. But the total amount of power the battery is able to store and return over it's life is nearly constant. You get to decide whether to use it in lots of small chunks or fewer big chunks.

So my question, when looking at Carbon Foam batteries, is whether they really are any different, or if this phenomenon that has characterized lead acid batteries for the past 120 years is just being exploited for the first time.

On a boat, DOD matters, but I think the whole acceptance charge cycle of AGMs is the far bigger "problem". Our quest for giant battery banks is all about reducing generator time at anchor. If you run your generator long enough to charge the batteries the last 20%, you will incur a LOT of generator run time. And if you don't do the last 20% of charge, you lose another 20% of you banks capacity. So in practice you run your batteries between 50% and 80% DOD, so only utilize 30% of their capacity.

If our batteries could accept full charge rate right up until they are full then we would care a lot less about generator time, mostly because it could be utilized well. This is the huge attraction to LiFePo batteries.

So I think the other big question with Carbon Foam is what their charge acceptance characteristics are.

And then of course there is their long term life expectancy, cost per AH over their life, etc.
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Old 05-23-2016, 07:09 AM   #24
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IMHO - A dead horse van only be beat until it is pulverized.


AH in, AH out, Charge levels, Charge rates, Charge times, Weight factors, Storage factors, Durability, Life-span, Hookups, Initial and ongoing costs, Charger capacities, Charger types... and all the rest:


With negative exceptions of some safety factors and with positive points on other safety factors... Well manufactured and maintained LA deep cycle batts are simply the most affordable and overall best lasting bunch in the crowd for house banks.
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Old 05-23-2016, 10:06 AM   #25
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I agree with Twistedtree.

These batts may be a step change better than traditional LA, but then so is their price.
On the other hand, so are LiFePO4 batteries.

So the real question is, how do these compare to LiFePO4 batteries?
Lithium batts also have many advantages, long life, deep discharge (80+%), efficiency, and also low weight. They are of course a lot more expensive than LA, but are they more than Carbon foam?
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Old 05-23-2016, 11:12 AM   #26
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Ben Ellison on Panbo.com recently did a long blog/discussion on the Carbon Foam batteries.
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Old 05-23-2016, 02:38 PM   #27
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So my question, when looking at Carbon Foam batteries, is whether they really are any different, or if this phenomenon that has characterized lead acid batteries for the past 120 years is just being exploited for the first time.

On a boat, DOD matters, but I think the whole acceptance charge cycle of AGMs is the far bigger "problem". Our quest for giant battery banks is all about reducing generator time at anchor. If you run your generator long enough to charge the batteries the last 20%, you will incur a LOT of generator run time. And if you don't do the last 20% of charge, you lose another 20% of you banks capacity. So in practice you run your batteries between 50% and 80% DOD, so only utilize 30% of their capacity.

If our batteries could accept full charge rate right up until they are full then we would care a lot less about generator time, mostly because it could be utilized well. This is the huge attraction to LiFePo batteries.

So I think the other big question with Carbon Foam is what their charge acceptance characteristics are.

And then of course there is their long term life expectancy, cost per AH over their life, etc.

I think their literature says both cycles at %DoD and acceptance rate are about like any other AGM.

The feature that seems to ring a lot of "cruisers" bells is the part about being OK to operate for long periods at partial state of charge (PSOC).

That's tied to acceptance rate, of course, but for many who are away from the dock for long periods on end -- and maybe this is the "without solar/without wind generator" crowd -- getting that last 10-20% (whatever) appears to be the hurdle.

Whether that's worth the cost premium...

???

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Old 05-23-2016, 02:43 PM   #28
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With negative exceptions of some safety factors and with positive points on other safety factors... Well manufactured and maintained LA deep cycle batts are simply the most affordable and overall best lasting bunch in the crowd for house banks.

Building on that...

Not sure about overall best lasting, but otherwise... Yep.

Except when they're a pain in the neck because access makes service difficult.

And then sometimes those safety features are attractive, even if not completely critical. An example might be something like thruster batteries installed under the master berth... where avoiding off-gassing might be a welcome benefit.

Comes back to your point about cost... but while that can often be measured in cycles@%DoD... the value of some of the other benefits is more elusive, more personal, more situationally-dependent...

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Old 05-24-2016, 05:00 AM   #29
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"benefits is more elusive, more personal, more situationally-dependent.."

Most of the operational results can be had with a std LA battery bank and a SOC ,state of charge meter ..

An SOC meter is the first item that should be installed on any boat that will overnight with out dock power.
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Old 05-24-2016, 06:56 AM   #30
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"benefits is more elusive, more personal, more situationally-dependent.."

Most of the operational results can be had with a std LA battery bank and a SOC ,state of charge meter ..

An SOC meter is the first item that should be installed on any boat that will overnight with out dock power.

Yep, when focusing mostly on "operational results."

But a SOC meter isn't going to climb down into our bilges and hump itself over stuff to get to and then manipulate battery fill caps, check levels, add distilled water if necessary...

That too could likely be fixed with a battery watering system, of course.

But I've found AGMs easier.

Everyone else's MMV.

And FWIW, given we usually don't anchor out for more than a week at a time... I haven't found not having a SOC meter to be any great loss. We have to run the genset to cook twice a day anyway, so we're going to make hot water and charge the batteries at the same time...

So any additional info a SOC meter gave me wouldn't really affect our activities.

Probably lots different for folks who stay out several weeks or even months at a time... so my point is that there's likely a threshold where a SOC meter becomes more useful... even important... but not everyone crosses that threshold.

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Old 05-24-2016, 07:18 AM   #31
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"benefits is more elusive, more personal, more situationally-dependent.."

Most of the operational results can be had with a std LA battery bank and a SOC ,state of charge meter ..

An SOC meter is the first item that should be installed on any boat that will overnight with out dock power.
I have a multi meter hooked into my parallel wired house bank of 4 deep cycle 31 wet cell batts. Check it often while utilizing electricity from batts; also while charging batts. Don't let discharge go beyond 50% before full recharge by one means or another. After full charge (I slightly over charge them) I let batts rest/settle for 30 to 60 minutes with no draw on their energy to check and see if they held a full charge. If not, I will pump more energy into them until they do reach/hold full charge.

To me... lit dial multi meter hooked directly into house bank is simplest most efficient and least costly way to keep close eye on battery charge levels. I also have multi meter in engine compartment for manually checking other batteries... with little need to do so, because they are always kept at full charge by means.

Another hint for simplicity - My house bank readily starts my engines. No need of a starter batt for engines. I do keep independent 27 starter batt on gen set; it charges in two ways... one is solar. Then I have a completely isolated 27 emergency batt in it's own black batt box that sits idle but is kept at 100% charge. This is just incase all else fails I have ready spare. It worked well couple years ago when our tow behind runabout's batt crashed... the new spare batt was quickly installed... and... off we went to play.
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Old 05-24-2016, 08:37 AM   #32
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After reading about these on a marine electronics review site I thought they might make sense at $426 but with the recent price increase to $486....forgetaboutit.
Just too expensive for me.


Arch
When looking at Firefly batteries don't forget to include the fact that they are designed and intended for PSOC use to 80% DOD, then cycled back to 80-85% so you are actually using 60-65% of the battery, even when out cruising, vs. just 30-35% with other flooded or AGM batteries.

Also that 80% DOD often chops an entire AGM out of the equation so the $486.00 per battery becomes a much more equivalent deal when you need only three vs. four of the competitors.

The cost of lead acid batteries, not just AGM, can not be judged on the box price alone. Ah capacity, projected cycle life, usable capacity, and lifetime watt hours or Ah's delivered are what will determine actual battery cost over the long haul. Many of my sailboat customers can murder batteries in less than 100 cycles regardless of flooded or AGM and this is due to PSOC use & sulfation.. Many of my trawler customers can murder them in less than 150 cycles for the same reasons. Was on a GB-32 yesterday and the flooded deep cycle Trojan's were sitting at 12.32V when I got on-board. They are three years old and ready for the recycle bin. Why? PSOC abuse.

The box price for Firely is now certainly higher than other premium G-31 AGM's (Lifeline, Odyssey, Northstar) but box price alone does not equate to value.

If you want to consider East Penn a premium AGM please read the May 2015 issue of Practical Sailor and see how they dealt with PSOC abuse.

When you consider that the other batteries should only be cycled to 50% DOD, in order to maximize cycle life, and they don't handle PSOC use nearly as well, it certainly makes a strong case for these batteries not costing as much as they may appear to, when judged only on the per unit price.

For example: (current street price from my distributors)

Three Firefly G-31's = 330Ah - At 80% DOD = 264 Usable Ah's - $486.00 X 3 = $1458.00

Four Lifeline G-31's = 420Ah - At 50% DOD = 210 Usable Ah's - $370.00 X 4 = $1480.00

Four Odyssey G-31's - 400Ah - At 50% DOD = 200 Usable Ah's - $377.00 X 4 = $1508.00

Four Northstar G-31's - 404Ah - At 50% DOD = 202 Usable Ah's - $390.00 X 4 = $1560.00

Also with the Firefly battery at 80% DOD this means you are in the very efficient bulk charge stage (constant current) far longer than if we started at 50% DOD. This means considerably more usable energy can be returned to the bank in a shorter time frame than with an AGM that is only cycled to 50%.

I have a fair number of Firefly banks out there, I even run one on my own boat as a reserve bank, (LiFePO4 primary) and a lot more scheduled to be installed and I can see the value in them for certain types of cruisers...

I still install a lot of Lifeline, Odyssey, Northstar, Trojan, Crown & US Battery etc. too.

I buy my Firefly batteries From Bruce at Ocean Planet Energy but he has a number of distributors throughout the US. If you are in the Chess Coastal Climate Control is also a Firefly dealer.

When Bruce first mentioned the Firefly battery to me I basically called BS on it. I then designed a test protocol to simulate typical marine use that I witness on cruising sailboats to see if it was actually any different than the other AGM's. Unfortunately my assumptions about the Firefly were misguided and wound up eating crow on my BS call...

Partial State of Charge Test May 2015

Partial State of Charge Test August 2015

I believe myself and Nigel have the oldest Firefly's in the marine market and both of these banks have had the living snot beaten out of them. Both Nigel's bank and my own Firefly's still capacity test at 100% of initial tested Ah capacity.

I no of know other battery, flooded or AGM I can say that about. Even GEL batteries don't stand up to the cycling abuse I have thrown at the Firefly's, and GEL's are excellent deep cycling batteries despite needing very careful charging.

Despite only being a few years into Firefly, in the marine market, they definitely do separate themselves from the pack when dealing with a PSOC environment.

For trawlers the reduced weight of additional batteries and PSOC are a bit less of an issue than they are for sailboats, but still can be important for those who cruise regularly.
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Old 05-24-2016, 08:50 AM   #33
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Thanks for your post. Any thoughts on footprint comparing Firefly to Trojan T105s? For me, utilizing same battery boxes with more stored power is attractive.
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Old 05-24-2016, 08:50 AM   #34
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When looking at Firefly batteries don't forget to include the fact that they are designed and intended for PSOC use to 80% DOD, then cycled back to 80-85% so you are actually using 60-65% of the battery, even when out cruising, vs. just 30-35% with other flooded or AGM batteries.

Also that 80% DOD often chops an entire AGM out of the equation so the $486.00 per battery becomes a much more equivalent deal when you need only three vs. four of the competitors.

The cost of lead acid batteries, not just AGM, can not be judged on the box price alone. Ah capacity, projected cycle life, usable capacity, and lifetime watt hours or Ah's delivered are what will determine actual battery cost over the long haul. Many of my sailboat customers can murder batteries in less than 100 cycles regardless of flooded or AGM and this is due to PSOC use & sulfation.. Many of my trawler customers can murder them in less than 150 cycles for the same reasons. Was on a GB-32 yesterday and the flooded deep cycle Trojan's were sitting at 12.32V when I got on-board. They are three years old and ready for the recycle bin. Why? PSOC abuse.

The box price for Firely is now certainly higher than other premium G-31 AGM's (Lifeline, Odyssey, Northstar) but box price alone does not equate to value.

If you want to consider East Penn a premium AGM please read the May 2015 issue of Practical Sailor and see how they dealt with PSOC abuse.

When you consider that the other batteries should only be cycled to 50% DOD, in order to maximize cycle life, and they don't handle PSOC use nearly as well, it certainly makes a strong case for these batteries not costing as much as they may appear to, when judged only on the per unit price.

For example: (current street price from my distributors)

Three Firefly G-31's = 330Ah - At 80% DOD = 264 Usable Ah's - $486.00 X 3 = $1458.00

Four Lifeline G-31's = 420Ah - At 50% DOD = 210 Usable Ah's - $370.00 X 4 = $1480.00

Four Odyssey G-31's - 400Ah - At 50% DOD = 200 Usable Ah's - $377.00 X 4 = $1508.00

Four Northstar G-31's - 404Ah - At 50% DOD = 202 Usable Ah's - $390.00 X 4 = $1560.00

Also with the Firefly battery at 80% DOD this means you are in the very efficient bulk charge stage (constant current) far longer than if we started at 50% DOD. This means considerably more usable energy can be returned to the bank in a shorter time frame than with an AGM that is only cycled to 50%.

I have a fair number of Firefly banks out there, I even run one on my own boat as a reserve bank, (LiFePO4 primary) and a lot more scheduled to be installed and I can see the value in them for certain types of cruisers...

I still install a lot of Lifeline, Odyssey, Northstar, Trojan, Crown & US Battery etc. too.

I buy my Firefly batteries From Bruce at Ocean Planet Energy but he has a number of distributors throughout the US. If you are in the Chess Coastal Climate Control is also a Firefly dealer.

When Bruce first mentioned the Firefly battery to me I basically called BS on it. I then designed a test protocol to simulate typical marine use that I witness on cruising sailboats to see if it was actually any different than the other AGM's. Unfortunately my assumptions about the Firefly were misguided and wound up eating crow on my BS call...

Partial State of Charge Test May 2015

Partial State of Charge Test August 2015

I believe myself and Nigel have the oldest Firefly's in the marine market and both of these banks have had the living snot beaten out of them. Both Nigel's bank and my own Firefly's still capacity test at 100% of initial tested Ah capacity.

I no of know other battery, flooded or AGM I can say that about. Even GEL batteries don't stand up to the cycling abuse I have thrown at the Firefly's, and GEL's are excellent deep cycling batteries despite needing very careful charging.

Despite only being a few years into Firefly, in the marine market, they definitely do separate themselves from the pack when dealing with a PSOC environment.

For trawlers the reduced weight of additional batteries and PSOC are a bit less of an issue than they are for sailboats, but still can be important for those who cruise regularly.
Ahhh...the voice of logic, expertise, and experience. Thanks for taking the time to share that
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Old 05-24-2016, 09:14 AM   #35
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CMS

Thanks for your post. Any thoughts on footprint comparing Firefly to Trojan T105s? For me, utilizing same battery boxes with more stored power is attractive.
Unfortunately, for now, the Firefly is only available in a standard Group 31 format. The T105 is a standard GC2 size or about the same foot print as a Group 24 battery, only taller.

The Firefly is not going to be a fit for everyone or every application but if you can take advantage of its benefits, and it fits physically, then it's a good option.
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Old 05-24-2016, 09:34 AM   #36
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Unfortunately, for now, the Firefly is only available in a standard Group 31 format. The T105 is a standard GC2 size or about the same foot print as a Group 24 battery, only taller.

The Firefly is not going to be a fit for everyone or every application but if you can take advantage of its benefits, and it fits physically, then it's a good option.
We have Firefly but only a very short time so not a lot of experience with them. We felt the standard Group 31 batteries installed at the factory were inadequate but wanted to improve without making a lot of other changes such as rearranging or adding or rewiring. So, we gambled on Firefly as the simplest solution. They fit physically so were the simplest and most cost effective solution assuming they perform as advertised. Time will tell.
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Old 05-24-2016, 10:16 AM   #37
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For those who have separate house and starting banks...would one Group 31 Firefly have enough cold cranking oomph to replace a 4D wet cell, or would two be recommended? (Our 100hp engine starts easily, so far, and because of the warming effect of the Pacific Ocean the engine room never goes below freezing even if it's -20C outside.)

This might be where the overall long term cost savings has a bit of a breakdown?
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Old 05-24-2016, 10:31 AM   #38
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CMS, Thanks for the great post with some very good information. I am a fan of wet cells as they are cheap, simple, known quantity, and I am a cheap and simple guy. However, my house bank batteries are 6 year old sealed wet cells. They are also inconveniently located if I were to replace them with 6v Golf carts. I would need to either install a watering system, or go with a no-watering battery. The most impressive argument you made was the usable Ah.

Hopefully, my current batteries will live for another few years. Then I will be looking at replacing a bunch of batteries and will do a complete re-evaluation of my system. The Fireflies will definitely be in consideration.

The other advantage as far as cost, is that I am seriously considering some solar to help with getting that 10% of full charge on the batteries. Since the Firefly handle PSOC so well, that isn't as important and could save me the time, expense, hassle, and roof-top real estate of installing solar.
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Old 05-24-2016, 11:35 AM   #39
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The most impressive argument you made was the usable Ah.
While that is a good argument the one that I really like is the ability to utilize your charge sources considerably more efficiently and effectively by keeping them in bulk/constant current for far longer than an AGM cycled to only to 50% DOD.

Bulk charging is darn near 100% efficient meaning almost every Ah you put in during bulk is removable during discharge. In reality it is up in the 98-99% +/- range for input to output.

When you consider that a standard AGM, such as a healthy Lifeline, when charged at .4C or 40% of Ah capacity, from 50% SOC will only remain in bulk for about 19-20 minutes before attaining absorption voltage the 80% DOD becomes a real game changer in usable capacity to time spent "fast charging".

By cycling to 80% DOD this makes considerably better use of the alternator or large inverter/charger or even multiple chargers.. With a .4C charge rate from 50% SOC (AGM batteries are often bought for their high charge acceptance) this makes the alternator useful for replacing about 13-15% of the bank capacity in bulk before being limited by voltage and seeing your CAR (charge acceptance rate) begin to decline.

By discharging that same battery to 80% DOD we remain in bulk for approx 42-45% of the usable capacity range and make considerably better use of our charge sources full potential, especially if idling the engine or running a genset to push large inverter/chargers to recharge. When cycling to only 50%, with a high charge rate such as .4C, your CAR begins declining in the mid to low 60-65% SOC range.

So charging for an hour from 80% DOD with a .4C sized alternator yields nearly everything you put in that can now be removed in usable energy. Almost none of that hour was wasted by a declining charge efficiency & declining CAR.. From 50% DOD you don't get nearly as much usable energy out of that hour of fuel....
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Old 05-24-2016, 11:46 AM   #40
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For example: (current street price from my distributors)

Three Firefly G-31's = 330Ah - At 80% DOD = 264 Usable Ah's - $486.00 X 3 = $1458.00

Four Lifeline G-31's = 420Ah - At 50% DOD = 210 Usable Ah's - $370.00 X 4 = $1480.00

Four Odyssey G-31's - 400Ah - At 50% DOD = 200 Usable Ah's - $377.00 X 4 = $1508.00

Four Northstar G-31's - 404Ah - At 50% DOD = 202 Usable Ah's - $390.00 X 4 = $1560.00

Extending this a little...

I've been considering -- bordering on actual planning -- to change our starboard bank from 3xG31s to 4xGCs whenever the current AGMs bite the dust. These would be for starting one engine, running half the house load, and running electronics suite on the bridge.

At first glance, that looks like ~300 Ah for the 3xG31 bank, versus ~440 Ah for the golf cart bank.

With most AGMs, that would look like:
- 300 Ah @ 50% SOC = 150 Ah routinely usable
- 440 Ah @ 50% SOC = 220 Ah routinelyusable

OTOH, 3x 12V Fireflies in the analysis:
- 300 Ah total, at 80% SOC = 240 routinely usable Ah
- 440 Ah @ 50% SOC still = 220 Ah routinely usable

And then there's the cost of 3x Fireflies versus something like the 4x Lifeline 6V AGMs. Probably some weight difference, overall. (Haven't done those comparisons).

And then there's the idea of 6V Fireflies, perhaps sometime in the future:
- 440 Ah @ 80% SOC = 352 routinely usable Ah

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