Another regular “work week” for the crew of Möbius this past week so not too much in the way of a Show & Tell post. So I’m going to use this week’s update to cover the recent demise of FireFly Batteries both as a business and on Möbius. Not sure that this will be of too much interest to too many of you so feel free to speed read or skip this weeks posting and I’ll have something of more universal appeal next week.
I must have jinxed it in last week’s update where I talked about how ideally cool the temperatures are here in Kalymnos, as the past week Mother Nature turned the thermostat up a touch and we hit a high of 35C/95F on Friday. Still not anywhere near what most others in Europe and elsewhere in the world are experiencing though! Daily highs have been dropping a degree a day since then and the Meltemi winds have been blowing hard every day so keeps a good breeze flowing through the boat and makes it pretty comfy onboard. 
Christine continues to have her daily swim and knee calisthenics and thinks her knee is ready for longer walks now so that will help change up her daily routines.
You can’t see it for the other boats but FYI, Möbius is just above the unicorn’s horn here.
I made some progress with the rigging for the Paravanes but most of my time was consumed with working out the best Goldilocks way to rig them, particularly for retrieving them and I’ll hopefully get time this coming week to install the actual rigging and have that to show you in the next update.
Summary of Möbius’ Electrical System
For a quick refresher and provide some context for what I’m about to discuss, here is a schematic of the overall DC electrical system in Möbius. (click any photo to enlarge)
We are a “DC based boat” in that pretty much all our electrical power, both 12+24V DC and 120V+240V AC originates from our 24 volt x 1800Ah House Battery bank. We do have the ability to plug into shore power when in marinas but the majority of time we are on anchor and even when in marinas we don’t usually plug in as it is much easier and cheaper to just power everything from our 24 Volt House Bank.This House Bank is made up of 24 individual L15+ FireFly Carbon Foam 4V/450Ah cells which when wired as per this schematic creates the 24V x 1800Ah or 43.2 kWh battery bank.
In THIS post last year I outlined how and why we decided to go with these FireFly batteries rather than traditional AGM or Lithium so please check that out if you are interested in those details. Short summary is that these Carbon Foam batteries were the just right choice for our use case as this chemistry is eXtremely efficient, safe and tolerant of cold temperatures and partial states of charge.
They are heavier and larger than most other batteries but we built the battery compartments integral to the hull on either side of the keel bar.
In addition to being a well cooled and secure location the batteries provided a very useful form of lead ballast and thus their weight was a feature and not a “bug” for Möbius.
Keeping this House Battery charged is primarily accomplished by our 4.4kW array of 14 Solar Panels and this can be supplemented by the 12kW available from the two 24V x 250A Electrodyne alternators whenever Mr. Gee is running. We have been using this system every day since the boat was launched a year and a half ago and has proven to work very well.
Until they didn’t!
Restoration Charging
Several months ago I noticed that the batteries had lost some of their overall capacity and so I performed the “Restoration Charge” that is recommended and outlined very thoroughly in the FireFly User Manual. The Restoration Charge involves doing a deep discharge of the batteries, pretty much flattening them, followed by a very high amperage Restoration Charge.
As per the second schematic above, the 24 batteries are divided into four 24V @ 450Ah or 10.8kWh Groups each consisting of six 4V @ 450Ah cells/batteries. Each Group can be connected On/Off with individual battery switches which enables me to charge them one Group at a time with the very high rate Restoration Charge of about half their overall 450A capacity, commonly referred to as .5C. Being able to apply such large amperage charging is one of the other big advantages of Carbon Foam and Lithium based batteries and can accept charging rates as high as 1C meaning charging at the rate of the full capacity of the battery. IF you have the ability to generate these high amperage charging it allows you do dramatically reduce the overall charging time.
In the case of a boat such as Möbius that primarily uses solar charging, this rapid rate of charge is not really an issue or a benefit because the solar panels fully recharge the batteries almost every day. However, having the ability to generate high amperage charging (.5C or above) that this Restoration Charging process requires, via either our three shore powered Victron MultiPlus 120A chargers …..
……… or the two 24V x 250A Electrodyne alternators, which made it relatively easy to perform these Restoration Charges. Based on my research and speaking with other owners who have FireFly batteries this Restoration Charging can be used any time that the capacity of the FireFly batteries goes down and only seems to be needed every few years if at all.
It worked just as promised for the first two Groups and in fact restored to a bit more than 100% of their rated 250A capacity. However the third and fourth Groups I performed this Restoration Charge on did not recover. I repeated this Restoration Charge process a second time on both Groups but to no avail and their fully charged capacity remained very low at less than 100A. I spent quite a lot of time both researching this situation and testing the individual 4V cells and all the cabling, connections and readings checked out properly with no significant differences between cells other than their capacity.I spent a LOT more time on all this as we literally live off these batteries, but after discussing with many other FireFly owners and speaking to FireFly technicians, the conclusion was that the Quality Control issues that have plagued FireFly batteries for several years had come home to roost on Möbius and 12 of my 24 batteries were defective and would need replacing. Not the news I wanted but at least FireFly has a good warrantee program and would cover most of the cost of replacing these batteries right?
This too started out promising with my Email discussions with FireFly International but quickly faded into less and less responses and then complete silence and lack of any responses.
Bye Bye FireFly?
I don’t know the exact details but as best I can tell FireFly batteries don’t appear to be available at all anymore and the company appears to be out of business. I can not find any official news or reports on this from FireFly themselves or in the media, but after even more research, here are some of the details I can provide in the hopes that this might help other FireFly owners or those considering purchasing them.
- All of the Email addresses I have for both individuals at FireFly as well as generic ones such as “information”, “Sales” and “Contact”, all of which had been working up to about the beginning of June are no longer working and return with permanent errors. No response to any Emails from me for over two months now.
- Rod Collins, highly respected marine electrical expert and owner/founder at Ocean Planet Energy and Marine How-To, posted on the FB Boat Electrical Systems Feb 8, 2022 (2) Boat Electrical Systems | Elsewhere on the net there have been discussions about FireFly batteries and their availability | Facebook
- They (FireFly) began having some warranty issues that they never had when they were made in the USA. The current owner of the company has run a great product into the ground. So after years of investing lots of time & energy into what can be a great product, yet receiving little support from the manufacturer, OPE decided to throw in the towel. If OPE was no able to get quality batteries, and they were spot testing every shipment. A DIY stands even less of a chance when ordering direct from India..Sad but This is what happens occasionally with off shore manufacturing..
- FireFly US website suspended Account Suspended (fireflyenergy.com)
- FireFly batteries No longer available from US based Fisheries Supply (see bottom) Firefly Battery FFL16+2V/4V | Fisheries Supply
- WakeSpeed no longer able to support or offer profiles for as per WakeSpeed founder Al Thomason Email to me
- FireFly batteries no longer available from Pacific Yacht Systems in Vancouver Pacific Yacht Systems: Shop Boat Marine Electronics and Electrical Products (pysystems.c
- long thread in Cruisers Forum FireFly Battery Long Term Users – Speakup – Page 9 – Cruisers & Sailing Forums (cruisersforum.com) with many having the same problems and lack of responses now.
Where to From Here?
You may well be asking yourself, where does this put us for a solution to replacing our FireFly batteries on Möbius? I know I am certainly asking that question!
For the time being, several months now, we are up and running without much problem. I purposely oversized the overall House Battery capacity to be 1800Ah / 43.2kWh and this is now proving to be very helpful. I have all four Groups connected as a single House Battery, which I’d estimate combine to give us a bit more than 1000 Ah or 2.4kWh total capacity. In these summer months, the solar panels bring the House Bank back to 100% by noon or earlier every day and I think that we can continue to have the boat be very livable with all our electrical systems, cooking, etc. fully operational on this reduced overall capacity for quite some time.
It really is a shame that this company has not been able to build reliable Carbon Foam batteries and I hope that some other company acquires the patent and brings good quality Carbon Foam batteries back onto the market, but that would likely take years if it happens at all and battery technology is evolving rapidly all the while.
I do still REALLY like these Carbon Foam batteries and believe that this chemistry offers an eXcellent solution for use cases such as ours and so I am trying, without much success so far, to find out if there are any dealers who still have inventory of 12 or more of these L15+ size 4V FireFly batteries, that test out OK. I would then need to figure out how to get them delivered to me or me get to them but this would be the best option if available. If any of YOU reading this might know of a source for these L15+ sized FireFly batteries that might be taking up space in some dealers warehouse, PLEASE do let me know!
Switching over to another battery type would require a significant amount of time and cost but may be in our future now. Given that we have the space and can use the weight of batteries to our advantage, perhaps going with tried and true AGM or Gel, or perhaps going with the batteries I had originally chosen, 2V OPzV traction batteries would be the best solution?
And of course Lithium and LiFePO4 batteries and their related BMS systems are becoming more and more common and proven and perhaps a bit better value so that’s another option I’m exploring.
At the end of the day a boat, even a relatively new one, is still subject to the harsh reality of all boats wherein they ALL have ongoing problems and present ever expanding To Do list items so I guess this is just the latest one for us to solve.
For now I will put this out there as a question for all you fellow boat owners and those with experience in larger House Batteries such as we need on Möbius, to send along your thoughts, connections and recommendations and I will gratefully add these to my own research and let you know what we decide to do.
In the interim, we will continue to enjoy each other and our unique situation here in Kalymnos and remind ourselves of just how fortunate we are to have each other, to be where we are and to have this great home from which we get to enjoy sunsets like this!
-Wayne
“At the end of the day a boat, even a relatively new one, is still subject to the harsh reality of all boats wherein they ALL have ongoing problems and present ever expanding To Do list items so I guess this is just the latest one for us to solve.”
IMO, this needs to be engraved on the palm of the hand and read first thing every morning. That’s what maintenance in an ocean environment means.
And I don’t even need to ask how you know that John!
What a shame!
We too have a FireFly House bank (much smaller @ 12V 660 A/H). Having installed these in 2017, it’s worked well enough to think they should be good for a while yet but, I have been troubled by their tendency to drift down towards 12.1V at 50% SOC. This is always worse when we start a cruise after having them kept in a float state for a while. After a few cycles they get better at keeping the voltage up better; but, I’ve wondered whether one or more of the batteries are underperforming and considered testing each battery individually…
After reading your post, I see that we are on our own & will just have to make the best of it for now.
Next bank will definitely be LiPO4.
-evan
Hi Evan and I guess a dubious welcome to the FF Abandoned Club! I appreciate you sharing your experiences with FireFly batteries on your boat. Nothing better than first hand experiential learning and always most appreciative of those willing to share theirs.
My thinking matches yours and I just need to spend more time in the coming weeks to do more in depth testing of each individual 2V cell on these FF batteries to track down the specific cause of the problem. What I’m somewhat hoping to find is that it is just two or more individual cells that have failed and lost their capacity and if that’s the case then I can have six of the 4V batteries that have full capacity still and use them to create what I’m calling a “Group” of six 4V@450Ah batteries. This would let me have an overall House Bank consisting of 3 Groups that would combine to provide 24V@1350Ah or about 32.4kWh which would be more than enough to keep all the systems on the boat fully operational. If I can pull that off then I could run this way for the next few years and then figure out what’s the best option whenever it comes time for all these batteries to be replaced which should be years from now.
FWIW, I observed similar situation that you noted of loss of capacity as indicated by the “drifting” voltage as the SOC went down. Like you, this seemed to happen after the batteries had been on Float for an extended time such as when we left the boat for a few months to visit grandkids, family and friends in North America. Like you I’m sure I’ve been reading a LOT of what other FF owners have been writing on various forums and groups and this seems to be a common characteristic of these Carbon Foam batteries. Indeed the whole reason for having the Restoration Charge procedure is for situations when a FF battery loses its capacity like this. As was the case for two of my four Groups, the Restoration Charging worked like a charm and brought the batteries back to even slightly more than full rated capacity. Many other FF owners reporting similar good results when they have needed to do such a Restoration Charge, which has not been too often, measured in years usually, so reassuring to know that if/when needed you can bring FF batteries back to full capacity.
I’ve also wondered if our use case where the solar charging and/or being underway with alternators running, brings the House Bank back to 100% every day is perhaps contributing to an eventual loss of capacity where you would want to do a Restoration Charge? The FF User Guid has some mention of this situation where you have the batteries in Float charge for extended times so worth keeping an eye on. In your case sounds like you are bringing your batteries back up after a few cycles but if this continues or if you are not sure they still have full rated capacity, then you may want to consider performing the Restoration Charge process which is relatively easy to perform and quite well outlined in the FF manual.
I will keep posting the results, good bad or otherwise here on the blog as the situation with our FF batteries evolves. Please keep me posted as you learn more with yours.
-Wayne
Shame the FF bats, sounded quite promising, sure.
Easy and only choice for next ones, lifepo4 and maxwell supercaps for starting. No going back.
It really is disappointing alright Andy. I really do think that Carbon Foam offers a terrific solution and one that is even superior to LiFePO4 for use cases such as ours when size is not a factor, weight is bonus ballast and their much higher tolerance for low temp and other conditions is taken into account.
I’m holding out hope that I will find a way to end up with at least 18 FF batteries that have full capacity which I can combine to give me a House Bank of 24V@1350Ah which would work just fine to keep all systems fully functional so I’ll be doing more detailed testing in the coming weeks and let you know what I find.
-Wayne
Sorry to hear about the problems. My understanding was that. FF bats were a compromise between the old lead and the new LFP technologies. Newness, cost, and some silly insurance companies has delayed their wider acceptance: that and the fire risk of regular lithium batteries.
But LFP have so many advantages, once you have the charging systems worked out. Size, weight, ability to custom build, more useful capacity, ability to charge fully, quickly, and the lack of need to frequently charge fully.
Besides getting rid of the potential hydrogen, oxygen, and concentrated sulfuric acid leak (it doesn’t mix well with aluminum), I also got rid of the propane system, and all cooking is done by electric. It doesn’t heat up the boat like propane.
You can check your batteries for as much detail as you want, as often as as you want, or just set it and forget it. I use Bluetooth to monitor them.
A small bank in comparison: (1400ah), and 1600-1940watts of solar, but a much smaller, simpler boat. It doesn’t run air con (yet?).
In the long run, the cost is less than lead batteries.
About 2 dozen cruisers in the Philippines used our Covid time here to order LFP batteries. The factory was pretty responsive, but you need to document everything clearly. (The difficulty was how to ship them safely thru Manila!!). To my knowledge, none of the new battery owners would ever go back to lead.
Hi Rob, thanks so much for this input. Great to hear from you again.
I wouldn’t characterize the Microcell Carbon Foam or MCF chemistry to be a “compromise” per se, but in the context that “everything” is a compromise you’d be quite correct. What attracted me to MCF and still does, is how fault tolerant they are and IMHO about as bullet proof of any battery type we currently have. Lithium has higher density so they are smaller and lighter than the other types for the same useful capacity and these are hugely important benefits where space and weight are high priorities such as on catamarans and many boats. In our case the greater weight of the MCF was a “feature” rather than a “bug” as “bonus lead ballast”, we had plenty of space for them and could count on the batteries working well and charging well even in very cold conditions when in high latitudes without the need to add heaters or complex BMS and so these combined to make the choice of MCF FF batteries just right for Möbius.
However, NO battery is of much good if they don’t work and FireFly apparently struggled with getting Quality Control working consistently within their manufacturing when the FF company first began and moved their manufacturing to India in 2010. However by about 2018 or so, most of the experts in marine electronics thought they had resolved this and there were enough boats with these batteries working well and holding up in the rigorous testing being done, that FF batteries were now ready for “prime time” in boats and they were being installed in ever increasing numbers. Obviously this was not the case and there have now been enough instances where FF batteries have had QC problems that the dealer networks stopped ordering/installing them and it would appear that ultimately the FF company appears to have effectively at least gone out of business.
Glad to hear that LFP batteries have worked out so well for you and your boat. Still not sure it is the best fit for us and I’m still holding out hope that I only have a few FF batteries that have actually lost their capacity and will be able to continue using the good ones for quite a few more years and I’ll be updating all that here on the blog as it happens.
Like you, we have also gone to a single fuel boat, no gasoline and no propane so diesel only and very happy with that change.
Thanks again for sharing your experiences and hope you have many years of trouble free boating as you continue to sail the world Rob.
-Wayne
Btw, how can you tell from the FF batteries that the capacity is degraded – is it via the battery monitor monitoring the discharge curve or how?
I do have Victron BMV712s to monitor all the battery conditions and data so used that initially. Then doing the Restoration Charge where you fully flatten the batteries down to less than 21V and then do a rapid charge, gives you a count of amps out/in. I used both 8hur and 10hr discharge rates in my testing and Restoration charging which I think provides the most accurate assessment of overall battery capacity. Let me know if you think otherwise or have other techniques for assessing battery capacity?
Dear Wayne
I would like to share my experience and thoughts regarding traditional GEL house batteries:
I currently have a battery bank of nominal 1’500 Ah (C/10) @ 12 VDC. The brand is MASTERVOLT 2V MVSV GEL OPzV/VRLA. The claimed service life is 20 years @ 20 deg C and 10 Years @ 30 deg C. After roughly 7 years in service they start to quickly lose capacity which is consistent with the average temperature of over 30 deg C here in the tropics and I need to replace them soon. The batteries are fully charged daily by solar power (solar array of almost 4 kW peak) and I confirm that constant float by not using them makes them “lazy” and a few heavy usages are needed to revive them.
For a replacement MASTERVOLT, VICTRON and BSB come to mind, but I am not sure if VICTRON still makes/sells the big 2V GEL cells. I had a look into the BSB brand which seems promising if operated in warm/hot environment since they use an optimized acid density and lower charge voltage, details at http://www.bsbpower.com:8082/product/battery/tubular/33.html
You might not be a great fan of tubular 2V GEL batteries but they have a few advantages over e.g. AGM batteries: Better tolerance to warm/hot environment, much longer service life, they do not need to be recharged immediately after use, good charge acceptance – they are quit robust and reliable. They are quit expensive and very heavy although but that does not seem to be a problem in your application.
Best regards, Markus
Hi Markus, thanks so much for sharing your experiences with your GEL house batteries.
When we were first designing Möbius I had in fact chosen the same 2V OPzV batteries you have, as the best choice to use in Möbius.
As time went on, I had been keeping my eye on the progress of other battery types such as AGM and Lithium and became more and more interested in the Microcell Carbon Foam MCF batteries from FireFly. In the beginning I was concerned with just one company making these as they owned the patent, and at the time I did not think that these MCF batteries had been installed in enough boats or other applications to be proven enough in the “real world”. However by the time we were ready to order the batteries for Möbius in late 2019, there had been a dramatic increase in the number of FireFly batteries being installed by dealers across North America and Europe and there had been multiple evaluations and testing by the likes of Nigel Calder, Ben Ellison on Panbo, Rod Collins at OPE, Jeff Cote at Pacific Yacht Systems and their evaluations and testing had now convinced them that these batteries were now well proven and had met or exceeded all their tests over time. Along with more reports from other boat owners who had installed FF batteries on their boats, this was enough to convince me that these MCF batteries from FF were up to the challenge of meeting our requirements and use case so I decided to place the order.
We have been in Turkey and Greece so the air temperatures can get up to 40C in the summer months, however with our battery compartments being down well below the water line on either side of the keel bar, the battery temperatures stay much cooler, typically around 26C when fully charged and can get up to about 30C when being charged, so similar to your temps by the sounds of it. The bigger concern for us is cold conditions as we would like to explore some high latitude places in the future and this is one of the conditions where Lithium does not work so well and is causing several manufactures to now offer internal heating elements in their LiFePO4 batteries. I’m sure this would work but adds another layer of complexity to the equation and another potential failure point.
Interesting to read that you too have noticed the effect of long term constant Float seems to reduce capacity or makes them “lazy” as you said, but that as has been our case, they come back once cycled heavily a few times. The Restoration Charge seems to me to be a way of doing this kind of heavy cycle from fully discharged to rapidly fully charged and for batteries that are otherwise fine, this brings them back to full capacity as was the case for two of the four Groups that make up our House Bank. But there are obviously at least some of the 4V cells in the two Groups that are not responding to the Restoration Charge, which have apparently lost their capacity due to some kind of internal failure and so that’s what I’m dealing with now.
I’m going to be doing more detailed testing of each of the 2V cells in each individual 4V battery to see if I can identify which of these are defective and which are still OK and then if I can end up with six good ones out of these two Groups, I can use these to wire these together as a third 24V @ 450Ah Group and have a total House Bank of 24V @ 1350Ah that would be plenty to keep us up and running for at least a few more years before I need to replace them all. These MCF batteries are supposed to have a very long service life and so if I can bring the capacity back up to their rated 450Ah level we should be good for quite a few years to come.
So that’s what I’ll be working on next and will report back on my progress here on the blog. If this doesn’t work, my next best option is to see if I might be able to find some new 4V FireFly batteries that someone has in their inventory and then figure out a way to get them onboard. No leads on that yet but I’ll keep trying. If that doesn’t work then I’ll need to replace the whole House Bank with all new batteries and figure out which batteries will be the best choice for us. In that case I will definitely be considering going with 2V OPzV traction batteries as one of the possible choices as well as AGM and Lithium and figure out which ones fit us and our use case the best.
So stay tuned as this whole saga plays out and thanks again for your insights and experience with your OPzV batteries.
Wayne
You can have best of both worlds. Keep the (working) batteries you have, and build a parallel lifepo bank.
This way you always have a safe sink for excess energy and a source for doing the fast recovery charge the FF requires from time to time, yes?
Intriguing idea as usual from you Andy, thanks.
I see some of the benefits of such a dual setup and not too difficult to be able to setup switches to change over from one to the other for supply. What I’m less sure about is how to manage the charging of two different chemistries. All doable to setup separate charging profiles and switch these from one battery type to the other as needed but with three different charging sources; Solar/MPPT, Alternators/WS500 regulators, Shore Power/Chargers I’d worry about the complexity and time of setting this all up and potential for human error in switching them over. And to setup the Lithium batteries to be able to charge the FF as you noted, would require the addition of some 24V DC-DC chargers I think?
What are your thoughts on how you would setup such a dual battery type arrangement?
Charging I would split the system to two parallel systems.
MPPTs are easy as you have plenty of them, just split them how you like, 50/50 maybe?
Alternators, one each.
Shore chargers, split them between the banks roughly equally.
You could also install dum manual 1-0-2 -switches to strategic devices, both sources and loads, so you can switch between the banks.
Then everything connected to lifepo bank controlled by the BMS output, one dry contact for loads for the low voltage cutoff, one dry contact for charge devices for high voltage end of charging. If BMS suppors, could be two different end of charge levels, high charge to say 90% DOD and then lower charge (few MPPTs maybe) to finish off more gently to 100% DOD.
Get an parallel BMS, like Electrodacus or similar. This way the BMS is not in series with the battery, and you never loose power due to (unlikely) BMS failure. Carry a spare.
Then for the high current charging of FF, if you have enough power in the inverters (I have a feeling you do), could just use the shore charging devices, AC coupled?
Sounds pretty logical, yes?
Thanks for these detailed overviews of how you’d recommend configuring a dual battery chemistry setup of Microcell Carbon Foam and LiFePO4. Very KISS and sensible so that’s good and as a result to some extent is open for human error, aka me, in not setting all the switches correctly when changing from one to the other.
Right now I’m not sure it would be worth the time and expense to add a new parallel Lithium bank as I’m still unsure of how “good” the existing MCF batteries are. If as I’m going to need to replace them all in the next year or so, then I think it would make more sense to go all in with one chemistry for an all new House Battery setup.
Right now I’m going to be doing more testing on the existing FF batteries by taking the ones in the two banks that have lost their capacity, down to individual 2V cells by removing all the cabling and interconections and then let them sit for some time and test their at rest voltages to see if this identifies some specific cells that are low voltage. Right now, all 24 of the 4V@450Ah FF batteries have very little differences in voltage between them and the total at rest voltage of each Group of six also reads the same at around 25.8V. To the best of my knowledge this tends to rule out there being one or two faulty 4V battery in the Group. However, from talking to other long term FF owners, several of them have had similar test results and yet still had some or all of their individual FF batteries which had lost most all of their capacity and could not be recovered by Restoration Charges. The consensus of these owners and the experts out there who I respect is that the problem is internal degrading of the plates caused by lack of quality control during manufacture.
I will publish the results hen I have tested the individual 2V cells and can better evaluate the best course of action going forward.
For now, I am able to run all the electrical systems on the boat from the two Groups that still seem to have most of their capacity and our solar output brings them back up to 100% by the afternoon each day. We don’t have Shore Power where we are docked and in fact have not had shore power for almost all of the time since we launched other than when I was doing the round of Restoration Charges back in March. Of course the solar output will now start to decline as the solar hours each day are shortened but we expect to be making our way West across the Med by then and so the Electrodyne alternators will easily provide whatever the solar can not. IF I can maintain this situation and keep the boat fully functional for the rest of this year, then I am inclined to delay any significant change or replacement of the whole battery system until then.
However it goes, I will continue to provide updates here on the blog and continue to appreciate all recommendations and suggestions from you and others here of which I am most appreciative.
-Wayne
And by dumm 1-0-2 I mean as an example a main cutoff switch for the say navigation bus:
1 – supply from FF
0 – OFF
2 – supply from lifepo bank
Heck, if you want to go all fancy, you can add Meanwell capacitor module like DBUF20 or similar, you can switch “online” without powering down any of the devices. It supplies voltage for a few seconds and also buffers a lot of noise from the supply.
Hey mate, out of curiosity, I just loaded the firefly energy page and it works!
Thanks Shayne. I found the same thing a few weeks ago but unfortunately still no response to Emails and none of the distributors and dealers I’ve been able to contact are carrying FireFly batteries any longer and don’t have any in stock. I’ll keep searching a bit longer and see if I might find a supply somewhere but not looking good so far. I’ll post any changes to this situation and what I end up doing in the long run.
Thanks again for your kind update.
No worries! It sure doesn’t bode well, not sure how anyone would ever trust the company again. It’s upsetting that it’s left you in a predicament!
I recently purchased a boat with 3 Firefly batteries.
I’m not 100% sure to know how much capacity they have. The Victron monitor says I’ve used 155 amps and the voltage is 12.01. That seems to match the state of charge graph I found in the manual (50%=12V), so I guess they are full capacity. Would you agree?
For the restoration charge .. a regular charge profile drops the voltage down to float long before they get to .5 amps. I have a 50 amp controller. Does it make sense to set the charge controller for bulk charge of 14.5 and Float of 14.5 and then charge them one at a time and watch the amps? Appreciate your help.
Hi Marc, my apologies for such a delay in responding, our situation here in Greece has become quite the circus with Immigration and we are now over in Turkey so I am way behind with online comms.
Re your questions about your FF batteries, you are correct that at 50% SOC your batt monitor should show about 12.0V.
The Restoration Charge procedure is pretty straightforward and documented in the latest FF manual you can get online if you don’t have that updated version yet. I believe the most recent one is dated Aug 2021. As per that manual, the Restoration Charge procedure is as follows:
1. charge the G31 to 14.4V or the 4V/450AH to 4.8V and continue to charge until the current drops to 0.5 A on the G31 or 2A on a 4V/450AH
2. Apply a float charge of 13.5V(4.5V for 4V model) for 24 hours.
3. Fully discharge the battery to 10.5V (G31) or 3.5V (4V/450AH), and then repeat the same charge cycle
It is important to note that they want you to charge the batteries as quickly as possible, no less than .2C and preferred to be .5C Your G31 batteries are rated at 116A so the minimum charge rate of .2C would be 23A and the preferred .5C would be 58A so your charger should be up for the job but yes, you will need to perform the Restoration Charge on ONE battery at a time to get these charge rates.
Not quite technically correct but you can think of these Restoration Charges as being similar to “Equalization” charges on other LA batteries and this seems that a Restoration Charge is something that needs to be done to FireFly Carbon Foam batteries whenever they start to lose their capacity. The ONLY way to actually measure the capacity of these or any other battery is to do a full discharge test with a battery monitor connected that can count the Amps flowing In/Out of a given battery. That works out quite well for these Restoration Charges in that you have to do a full discharge (Step 3 above) and so just be sure you have your battery monitor, such as a Victron BMV711 that will show 0A consumed when it is at 100% SOC and then when you get it fully discharged and the voltage has dropped below 10.5V you can read the amount of Ah consumed. For the G31 this should be close to or even slightly above 116Ah but the reading will tell you how much capacity that battery has so you will know if the Restoration Chage was needed or not.
Hope this helps and let me know if you have more questions or ways I can help.
-Wayne
Sadly this rushed transition to electrification has brought along quite a few bad actors and shaky players that make buying batteries a frought endeavour. I was on the waiting list for GreenRock salt water batteries for about a year, decided to forgo putting a deposit for a product that hadn’t been produced yet let alone shipped. A few months ago when inquiring about delivery ETAs an automated response came back telling me that the North-American branch of the business was closing. At least they had the good sense to be open about what was happening, but I am glad I didn’t put in a deposit.
Astute observations about the “rushed transition to electrification” Maxime and I certainly agree. There are always “a few bad actors and shaky players” in any market I think but this “rushed” and unstable situation is going to be the norm for the foreseeable future as the race to find the next big innovations and solutions for electrical energy storage speeds up and the competition becomes ever greater. There is just SO much pressure and even more Billion$$$ being thrown at this problem, that I think we will all be in the pressure cooker type of situation for a long time. I’m actually encouraged by how much attention and $$ is being applied to energy storage solutions as our human history is rife with examples of how innovation is often able to solve such problems and improve our lives. Perhaps this is “just” the new normal we are all going to have to learn to adapt to?
However while we await the next great innovation in battery and other parts of the electrification movement, those of us who are very to extremely dependent upon a long lasting and reliable storage system will need to do our best to choose vendors and equipment that has been installed on enough boats and been through enough independent testing to earn our trust and purchases. Back in 2019 when the batteries for Möbius needed to be ordered, I changed the specification from OPzV to FireFly Carbon Foam because I thought that they had now reached that critical point. What I did not account for and not sure if I could have, was that the Quality Control QC problems they had experienced with their manufacturing, would return after previously being resolved and that ultimately the supply would dry up and the company would appear as best as I can tell, to have ceased operation.
I have not completely given up on our existing FF batteries and once I get the new engine installed and we get back underway I will try again to restore at least most of our 24 L15+ batteries to their original capacity or close to it. I continue to also search for a source of any remaining L15+ FF batteries out there in the world that I could perhaps purchase to replace any of ours which have failed permanently but no luck yet. And I will also get back to researching what battery type and manufacturer we will ultimately go for whenever we do need to replace our current ones. Lithium is the leading contender for most people and boats these days and remain on my list of potential candidates as well but there are other more “traditional” battery types that I’m considering as well.
Fortunately for now the existing FF batteries have enough capacity to allow normal life onboard and I hope to be able to continue that for at least the rest of this year if at all possible.
I wish you luck as your research continues as well and please do let me know what you find and if there are any that you think would be viable options for Möbius and our use case.
-Wayne
Interesting, and frustrating discussion. I’m now stuck with 6 G31 Fireflies, which seem to be suffering from the lazy battery syndrome. I have a Victon Multiplus which allowed me to get them charged and then leave them on the 13.2 volts while sitting at the dock. Which I dutifully did. And I shipped the graph of my batteries trying to go through the paces and failing miserably 20 amps at 4 hrs on my load test. The curve had a pretty much vertical asymptote at about 4 hrs, 5 minutes.
But then I found out that there was a whole new charging regimen when I spoke to someone at OP. Which was kind of frustrating as I was fastidious in keeping the old charging profile happening perfectly…only to find out that after 2021 the new Charging instructions say you’re supposed to put the batteries on 13.5 volts for 24 hours (which I would have totally freaked me out before, as I was generally given to understand that doing things like this would wreck the batteries).
I found this out week or two after a scarry experience–going west along lake Ontario, 6’11” draft, nowhere to duck into (the lake was low this fall ), a 35k squall out of nowhere, big waves, fuel sloshing around in the tank, eventually no engine and then 25k pretty much straight upwind to get home in the dark–all on batteries that we thought were fine, but then I started to notice some weird stuff with the battery curve (we have a Victron Cerbo it allows you to see this stuff on an account on their web site) . I took them to my supplier–he isn’t getting his batteries from OP (Canada…different source here I guess). He ran another load tests, confirmed what I had found, and asked what I had been doing. I showed him the graphs for the last 6 month (Again the Cerbo allows you to do this, you can see V. and A. for the last six months). My response to him, with graphs as proof, was that I was trying to be nice to my batteries…old school, 13.2 volts, not 13.5 for 24 hrs.
He’s now trying to track someone from FF. And he’s getting the sort of experience that you have been through Wayne, no body is responding.
I have tried the new charging regimen on the boat just before it came out and this didn’t seem to help. I have a 250 amp alternator, and a beautifully controlable Wakespeed regulator. I bout both with the fireflies in mind. You can, in theory charge the Firefly’s at 1c. So I had no trouble charge them at .5 C. per the new recommendations. But this was kind of closing the gate after the horse had left. It didn’t seem to help much.
My supplier is going to try running a desulfation cycle on these batteries to see if that helps. They’re toast, so may as well try. Wayne I’m wondering if you’ve still got some of these old batteries around, you could try this out and see if doing something like this helps. If you look up “desulfation Battery Charger’s” you will get an explanation of what they do, and how they do it: in a nutshell they kind of hammer away at the sulfated molecules with a brief hi voltage pulse. So a high frequency molecular jack hammer if I understand it correctly. And they’re cheap!: $125.00 (Canadian) gets you a NOCO charger from amazon with a desulfation cycle on it.
Maybe if a bunch of us mess around with these, in combination with the “driving it hard” and running them down quickly tactic (as suggested by some on the net) we will come up with a solution. The batteries are toast, it’s worth a try.
Another part of the problem is that we really don’t know anything about what’s going on chemically, or on the physical level inside the battery. As in what is the problem in manufacturing that people at OP are talking about. Is is some sort of impurity? Or a cheap version of lead or carbon or sulfuric acid? Or is something not made physically to spec. It would be good to know what the problem is? And what, if anything, can be done about it. It would be good if t they could explain this to us; we’re all ears; and we have some really expensive lumps of lead that they’ve sold us. They could at least talk. Be nice if someone could explain what’s up. Instead I’m getting the guy who described what’s going on per OP saying don’t take these out for a long sail, or a short scarry sail at night in Toronto (we won’t be doing that for a while, or (my worst dream) my wife will get of the boat and tell me “Dear: sell that thing. Now.”).
If we’ find anything, in our experiments we’ll get back. I’ve got till spring before I have to buy more batteries. If anyone hears anything, I’m interested.
Hi David, thanks so much for such a detailed overview of the problems you are experiencing with you FireFly batteries. Our form factors are different with you having the G31 12V models and me having the L15+ 4V ones but the Microcell Carbon Foam chemistry is exactly the same and sounds like the problems we are experiencing are pretty much the same as well. I hope that others reading this who have some experience or expertise with Carbon Foam FF batteries will add to this thread and that collectively we can help each other resolve this more successfully than we have been able to so far.
Just to be clear, I am not an expert on batteries or electrical, just someone who has a reasonable amount of experience and time researching and designing electrical systems for our new boat and others previously. Similarly, I’m no expert on FireFly nor Carbon Foam batteries but having now spent quite some time working on ours, researching the experiences of others and experimenting with various solutions and testing, I now know more than I ever wanted to about them and am happy to share in the hope of helping others and to prompt others to add to this discussion.
Sounds like you are very similar, having done a good deal of your own research, testing and reporting of your system so I won’t rehash the basics and just offer some additional observations I have, outline what I’m going to be doing with our FF setup and summarize what I’ve learned from talking with others and my experiences working on our setup.
While I don’t know that it has been “proven” based on my experiences and that of many others, now including you, I think that one of the most important lessons learned about these CF batteries is that quite counterintuitively, they do NOT want to be kept on Float or at 100% SoC for long periods of time. Lithium batteries also seem to have a similar preference, though obviously they are a completely different chemistry and type. I have come to this conclusion as what started the decline of capacity of our batteries when we left the boat for several months to fly back to Canada and the US for some family time there. We left the boat with very little electrical being left on and just some of the 14 solar panels turned on. The result was that the solar kept the batteries at 100% continuously for those 2+ months and not long after we returned I started to notice the decrease in capacity with the voltage dropping much faster than it should as amps were consumed and the SoC declined as it should.
Perhaps exacerbating the situation, for most months of the year where we were located around the Antalya Turkey area, our solar output brought the batteries back to 100% by late morning and stayed that way until the solar output dropped off in the early evening. This was all working as I had designed it to but I am now of the opinion that having a system that returns CF batteries to 100% every day and worse still keeping them at 100% for days/weeks at a time is actually harmful to these batteries and after operating in these conditions for several months, the capacity begins to decline from original and eventually drops off to the severe degrees you, I and many others have experienced. This all seems to be borne out by comments from others and from some FF experts and so I think the solution would be to design and program your battery charging system to NOT bring them back to 100% every day and rather stop the charging after they get to around 8o-9% SoC and then use them till they get down to 50-60% and then repeat the charging to that 80-90% level each day. Then perhaps about once a week or so, allow them to fully charge to 100% before going back to the PSoC regime.
As you noted, FireFly did change their manual and recommendations quite significantly around the end of 2020 or so and my comments above seem to be at least indirectly acknowledged by the updated (Aug 2021) User Manual in several sections such as:
Operation & Charging:
1. Firefly batteries can be operated in a partial state of charge for long periods of time
without sustaining any permanent damage but they must be charged completely and
quickly, periodically to avoid suffering permanent sulfation. See statement #11 below.
8. Charge V Settings:
You DO NOT need to fully charge the batteries each cycle in order to maintain the capacity however see the section
below on periodic fast & complete charge cycle recommendations.
I now interpret these two points to actually mean that you should NOT fully charge these batteries most of the time.
Then in Section 9 they specifically note that on boats such as mine, where we have large solar charging every day and large alternator charging every time the boat is being operated, that having the batteries in Float for extended periods of time is also NOT good:
9. Float-Charging: For charging sources that may be charging the battery for an extended period
of time (solar, or an alternator if motoring for a while); set the float voltage to 13.4V or 13.5V for
the G31 and 4.5V for the 4V 450Ah model.
Firefly batteries do not require a float charge on a
regular basis. However, if you are float charging, due to their longer projected lifespan, it is
important to keep the float voltage at 13.4V or 13.5V (4.5V for each 4V/450AH) to ensure the
battery lasts for as many cycles as possible. For this reason, Firefly batteries are not
recommended for applications using internally regulated alternators.
And then lastly in this section of the manual, they outline the need for:
11. Periodic Fast & Complete Charge Cycle Recommendations: Note that periodic fast (high
current) charging from a low state of charge can help restore usable capacity after periods of
repeated slow charging (less than 0.2C) or deep discharge cycles. It is recommended that the
battery goes through a complete charge cycle from a low state of charge every week if they are
being heavily cycled or at minimum every 30 days. Ideally the batteries will be charged at a
current of 0.4C (46 Amps for an Oasis G31) but a minimum of 0.2C (24A per G31 battery) is
acceptable. These charge cycles should end with a 24 hour float charge at 13.5V for the G31 and
4.5V for the 4V 450Ah model. For applications lacking fast charging capability, contact OPE or
for alternative restoration procedures.
I would summarize all of this to mean that the best way to use FF batteries is quite contrary to what we have all learned for lead acid based batteries and that CF FF batteries should be discharged and charged quite hard on a regular basis. You noted “…I was trying to be nice to my batteries…” but similar to diesel engines treating them “nicely” is actually ends up “killing them with kindness”. So as I said, if I were to be designing a battery system using FF CF batteries, I would size them and the charging such that they would be regularly taken down lower than 50% SoC and not regularly brought back to 100% nor left on Float for any length of time.
On the more positive side of things, FF did add a section in their manual on “Restoration Charge” that does seem to work to bring batteries that have lost their capacity back to full capacity or even greater. That process is relatively straightforward though can be difficult to achieve on a boat like ours which is our full time home. Those instructions in case you don’t have them are as follows:
Restoration Charge
As stated, Firefly Batteries can operate in a partial state of charge for long periods of time without sustaining any permanent damage.
The usable capacity will decrease, however, with each cycle within a partial state of charge, up to a point.
In order to regain the full original capacity and in some cases more, it is necessary to perform a restoration charge.
To perform the restoration charge: charge the G31 to 14.4V or the 4V/450AH to 4.8V and continue to charge until the current drops to 0.5 A on the G31
or 2A on a 4V/450AH and apply a float charge of 13.5V(4.5V for 4V model) for 24 hours.
Fully discharge the battery to 10.5V (G31) or 3.5V (4V/450AH), and then repeat the same charge cycle.
I followed this Restoration Charge procedure on my batteries when they first lost their capacity, and it worked very well and brought them back to even slightly better than their full rated capacity of 450Ah each. I suspect you’ve already tried this Restoration Charging but if not, I would recommend that you follow the process by fully discharging your batteries to 10.5 or less and then charging them at .5C or more. Note that others have found that it is sometimes necessary to do this Restoration Charge two or three times to bring the battery capacity all the way back to their rated capacity.
In my case, I have four groups of six 4V @ 450Ah cells/batteries for a total of 24 of these 4V cells and total capacity of 1800Ah @ 24V. Of the four groups, I was able to bring two of them back to slightly more than 450Ah but the other two groups did not respond to the Restoration Charging and their capacity remained very low. That was about 10 months ago and since then the “good” two groups also started to lose their capacity and I have not been able to recover them with Restoration Charging so I don’t think I’m going to be able to revive them. The “good news” is that these batteries do still have enough capacity left that along with all our solar and alternator charging, or when in marinas and shore power is available, I am able to keep all our electrical systems up and running so life onboard is still quite “normal”. My hope is that I can continue to nurse them along for the rest of this year and until we have crossed the Atlantic and am in a place where I can get new batteries delivered to the boat and go through the significant work of putting in an all new set of batteries.
Like you, we have plenty of charging capacity with 14 320W solar panels and two Electrodyne 250A @ 24V alternators also controlled by dual WS500 regulators. But the challenge in our case with doing these Restoration Charges is that being our full time home it is quite disruptive to have to turn off most electrical systems in order to fully discharge each of the four groups down to less than 22V. I’ve come up with ways of doing this but rather laborious.
Regarding “sulfation” that you mentioned, my understanding is that technically the chemistry of Carbon Foam batteries doesn’t allow for sulfation per se, however I think you are correct that a similar type of condition of loss of capacity DOES happen to these CF batteries when they are left on Float or 100% SoC for extended lengths of time. This would seem to be borne out by how the Restoration Charge outlined by FireFly is very similar to what a “desulfation” battery charger does for LA type batteries which is to charge them at a higher voltage and current. I am familiar with LA batteries in previous boats to this being referred to as “Equalization” charging. As you say, we don’t have much to loose by trying different methods, but I think that the Restoration Charging process is going to be the equivalent for CF batteries of doing Equalization or desulfation on LA batteries and that the specified discharge/charge rates and voltages outlined in the FF manual would be the better ones to use. However, typical Equalization charging of LA batteries involves holding a voltage of 15.5-16.3V for 6-8 hours and I’m not sure how CF batteries would respond to such high voltages? And I’m not sure if the ”desulfation” or “molecular jack hammer” chargers you noted would work on the very different chemistry of Carbon Foam? As you noted, “we really don’t know anything about what’s going on chemically, or on the physical level inside the battery. ” and I have given up trying to get any response from anyone at FireFly in the US or International or the factory so not sure if we ever will. I’m still not sure if the company is even still in operation and making new batteries so if you hear anything more about that please do let me know.
Regarding trying to recover our sadly depleted FireFly batteries, my sense is that it is more to do with the high rate of charge rather than the high voltage, to restore a CF battery that has lost its capacity. When I next get the time and situation where we are stopped for ahile, I will try one more time to see if I can revive at lest some of our 24 batteries by doing some repeated Restoration Charging by fully flattening the batteries and then charging them hard and fast at .5C or more and hold out hope that maybe, just maybe, they can be brought back to full or near to, rated capacity. Certainly, some people report having successfully recovered their FF batteries and it did work the first time for two of my groups of batteries so it’s possible.
We are now underway most of the time as we head West and out of the Med to cross the Atlantic next month so I won’t have access to any such new chargers till I get to the other side but please do keep me updated as you try these methods and I’d certainly love to find some new methods that have worked for you to recover your FF battery capacity.
FWIW, at this point in time, my plan going forward is to try to nurse our current House Battery of 24 FireFly CF L15+ batteries for the next few months until we get across the Atlantic and in a place where I have access to suppliers and transport to get a new set of batteries onboard Möbius. I have decided that it does NOT make sense to try to replace some or even all of our batteries with more from FireFly, even if they are available, as it seems to be too big a risk that another whole set of 24 batteries would all hold up and not have at least some of them fail. I have not yet decided what battery chemistry I will go with next, may be “back” to more traditional sealed LA batteries such as the OPzV Gel “traction” batteries I had originally planned to use on Möbius or if it makes more sense to go with Lithium. Weight and space are non issues for the batteries on Möbius, indeed the weight is a plus as part of our ballast, so the smaller size and weight of lithium is not an advantage for us so both Gel, AGM and Lithium batteries and all worth considering and I’ll keep researching this more and report here on the blog when we make the change.
Sorry I am not able to be of any more help to you or others out there with similarly loss of capacity of your FireFly Carbon Foam batteries. And thanks again for taking the time to send this detailed description of your situation and I encourage anyone else who has had some experiences, good, bad or otherwise with FireFly batteries to please add your comments and suggestions.
Thanks,
Wayne
Thanks for your thorough, comprehensive response Wayne. Much appreciated. I get the impression that we are all beta testers with a probably-really-good technology, that by the sounds of it, appears to have some production issues that’s getting in the way of sorting out exactly how they should be set up. After reading through your explanations, which, along with the new manual, my suggestions for and even newer manual should start with “Here is the most important things that you ABSOLUTELY SHOULD NOT DO: think of these as lead acid batteries. They’re not. Some fundamental practices that will help lead acid batteries last longer, will actually harm these batteries.” After which I would start enumerating some basic practices to stay away from, with, by the sounds of it, keeping these on any sort of a float charge as the first item. So a charging algorithm should shut off until some specified lower voltage is releases.
In terms of your FWIW: I am considering something similar as a solution; going with some sort of AGM batteries next spring, mostly because my R&D budget doesn’t exist and I can’t afford being part of this Beta Process any longer. Which is frustrating, as I think that this is a good technology, and once the bugs are worked out, and effective methods of charging for these batteries are made clear, they will be an effective–and relatively low cost tool. I’m not at all convinced that lithium is “there” yet ( with “there” being defined in terms of relatively low cost, reliable, effective, and manageable by plebs like ourselves). I suspect that a fair number of alternators will be the victim of load dumps, which will cost users in disruption, and rebuilds, or alternator replacements. Unless you have really good batteries, an effective BMS, that communicates properly with a good regulator, and it’s all set up by someone who knows how to build an effective, bulletproof system for making sure that all of this works together. Which is to say big bucks, and so much for the level of autonomy that I think most of us were hoping for with FFs.
In the meantime we’ll try and if we find anything, I’ll get back.
Thanks for this additional update on the situation with your FireFly batteries David. Some good ideas for whomever takes on overhauling FF to deal with the QC issues that seem to continue to plague them for several years now, or perhaps some new ownership will come along. Like you, I too think that this Carbon Foam chemistry is a great option that can offer the best fit for quite a few different use cases out there so I do hope that someone will find a way to bring some good quality CF batteries to the marketplace. However I don’t see that happening in time to help you and me and other boat owners who have FF batteries that have lost their capacity so we will need to find other solutions for replacements.
Similar to you it sounds, I remain in research mode for what chemistry and company to go with for the batteries to replace our existing 24 FF L15+ house bank batteries with AGM, Gel and LiFePo all being considered and then a long list of potential makes and models to go with. So far I am able to keep nursing the existing batteries along to keep all our systems up and running, knock on wood and fingers crossed that hopefully this will continue into the new year when we will most likely be across the Atlantic and in the Caribbean area with better access to battery suppliers. So please do keep in touch with me as your research and decisions evolve and I’ll do the same.
-Wayne
Hello Wayne,
Just responding to your observations with the FF batteries. I have 3 of the 31’s and they have developed exactly the same problem. At this point they will charge to max volts but, have minimal capacity. They worked well for a year. I have Solar to keep things charged up. Clearly they have never spent substantial time at partial state of charge. Exactly the opposite. They are my house bank, and in fact my standard AGM’s for engine and generator, are outperforming the FF with much the same parameters, but no deep discharges.
I do plan to try the recovery procedure, but will replace them with standard AGM’s. If I can get them to work(not optimistic), I will use them in an RV.
Speaking of RV’s, there is now a HUGE transition to lithium in that market.
State of the art is Victron equipment with Battleborn batteries, and solar charging. Battleborn has a 10 yr warranty and is built in the US. Basically about $9 per AH. Other cheaper brands exist, but these get consistently great reviews.
I don’t own any yet, and not endorsing them. But, we plan on getting an RV and will be installing Lithium assuming the FF are dead.
I have contemplated going Lithium on the boat, but it will require a lot of changes in my system I think, and would rather experiment in the RV first. Also the boat is a twin diesel cruiser, so need a dual system for charging the different chemistry.
Thanks for your very thorough and informative posts!
Randy
Hi Randy, thanks for this detailed overview of your FF battery setup and its problems. From my experience with our FF battery banks I have come to conclude, rightly or wrongly, that these Carbon Foam batteries are quite counterintuitive and somewhat the inverse of any other lead acid battery chemistry. Their big advantage for many use cases is that these FF or CF batteries don’t mind being in a PSoC for long periods of time and in fact what I think is the case is that one of the worst things you can do is keep these batteries fully charged for any length of time. They want, perhaps need, to be at a PSoC most of the time. You noted that “Clearly they have never spent substantial time at partial state of charge. Exactly the opposite” and so I suspect that this is actually the cause of the loss of capacity of your FF batteries. The good news is that performing a “Restoration Charge” as outlinedin the most recent FF manual, does tend to bring FF batteries back to their full rated capacity or even better so I can recommend that you be sure to do two or more Restoration Charges on your batteries and see if they respond and come back to full rated capacity.
I am in a similar position as you to some extent in that I obviously need to replace our 24 FF L15+ batteries with some other battery chemistry and my jury is still out on what that it. As with you, I think the choices boil down to just two; lithium or AGM, though I am also considering Gel type “Traction batteries”. For many of the same reaons you have noted I am leaning much more towards the AGM/Gel type as I just don’t have the use case to get the benefits from Lithium to justify their cost and complexity. To my way of thinking the primary advantage of Lithium is “power density” or size & weight. In our case on Möbius size and weight are not a problem and in fact the weight is a feature not a “bug” as it is used as part of our ballast. I am not at all against Lithium and I definitely see and understand their significant benefits for most boats but they do not match up with our use case and boat so I don’t think that the value proposition is there for us to go with Lithium. However, I’m still researching and “running the numbers” so this may change.
I think your plan to try out your first use of Lithium to your RV is a good one, much smaller scale and cost to try them out and have that critical real world experience with the overall battery/charging/monitoring/controlling system and see what that tells you about what would be the best solution for your boat.
Please do keep me and others here updated as you do both the Restoration Charge on your FF batteries and whatever you decide to do with your RV so we can all learn from your experiences.
Thanks,
Wayne
Hi Wayne,
I suspect that you are correct in your statement that your battery usage is not well suited to the Fireflies. Your ability to quickly get back to 100% SOC is not what they like and seems to quickly degrade them.
I note that the user manual now recommends against float charging if possible and using intermittent CC/CV charging profiles. This can work OK in my case as we use the boat on weekends and extended trips more intermittently; but when living aboard with ample solar and generator charging to bring it back to 100% SOC every day, they won’t be happy. LiPO4 also prefers to not be held at 100% SOC for long durations. The BMV can manage this but as I understand it, the chemistry is rather averse to a “Float at 100% as much as possible” strategy.
In our case, I would welcome LiPO4 as we are often out at anchor in the the wintertime with limited solar charging and so the ability to rapidly recharge with shorter generator runs would be ideal.
Not that my opinion counts for anything but in your case, on Mobius, the risk of having the batteries in a partial SOC for any duration is actually rather low. I think Gel or AGM would be a much better choice for your application. You would welcome the weight as ballast and your massive charging ability can keep them happily charged at or close to 100% virtually every day…
-evan
Thanks for these additional thoughts on our mutual problems with FF batteries Evan. I’d be curious to know what settings you have changed to in your chargers to try to eliminate or reduce the Float time charging? Now that we are having such good solar days we the “problem” of having so much recharging capacity is much greater now and so I’m going to try to keep experimenting with my charging parameters to see what I can do to force the MPPT controllers and the WakeSpeed 500 regulators from going into Float mode and bringing the batteries up to 100% every day. As you have I have both figured out this is strangely a bad thing for Carbon Foam and Lithium batteries it seems. More and more of the companies making LiFePo4 batteries are now publishing their charge profiles that specifically provide the best charging for their batteries so those seem to be working out but to the best of my knowledge these don’t exist for FF batteries. Indeed companies like WakeSpeed have removed the Carbon Foam FF profiles from their app so we now have to create our own profiles and upload them into the regulators manually.
I also saw that you were concerned about running your house bank battery voltage too low in order to do Restoration Charges or when the voltage sagged under high loads and worried about these low voltages causing problems with other equipment on the boat. As many on the TF noted, almost all electronics and electrical devices are unharmed by these times of low voltages and that has been my experience and understanding as well. Our AC inverters continue to put out their regular voltages pretty much no matter what the DC voltage is of the batteries they are inverting from and when you check the specs of most DC equipment, they list quite a large range of voltages which are acceptable, some down to as low as 8V in a nominal 12V device. In our 24V system on Möbius I have had the voltage get down as low as 20V for relatively brief periods and only the fridge/freezer components “complain” with a low voltage alarm at about 22.5V but from what I’ve read about these Danfoss compressors, the low voltage does not cause any damage, just that the compressor is not working at its regular efficiency. Not that I’m recommending running at such low voltages, just wanted to pass on my experiences and understanding that while undesirable, having peirods of low voltages does not cause any damage to most electrical equipment.
I look forward to hearing how you progress with resolving your FireFly situation and I will keep posting what I end up doing about ours. Right now I’m happy that I can continue to keep the boat’s systems working just fine, thanks in large part to all the good solar days we now have and buying me time to get to a better location for working on the best solution for our FF batteries.
-Wayne
Thanks Wayne,
Our Firefly bank is a baby compared to yours at only 660Ah but the chemistry is the same.
Thank you for referencing the updated manual, which had differing instructions and information than the original manual that came with the batteries in 2017. I did do a deep discharge to 11.2VDC (remarkably, this took a long time including some high draw discharges…think vacuuming the boat for 2+ hours on battery power…) I bailed out before getting lower as I was planning on getting out on the boat to re-charge and didn’t have the patience or time to wait longer. After a high current re-charge using the generator feeding 2 chargers + the engine alternator for a total of ~ 280A theoretical capacity, I am seeing the house bank maintain much better voltages for any given SOC. I think this has been a worthwhile exercise giving a significant improvement to the house bank performance.
I’ve also reprogrammed the primary charger (a Magnum 2812 Inverter/Charger) to a Constant Voltage / Constant Current Mode (CV/CC).The charger will only charge at a maximum voltage (14.4V) and rate for a maximum set period (~ 10 hours) or until the charging current drops below a selected threshold (< 10 A). It then goes into 'silent mode' with no float charging. The charging cycle resumes when the house bank voltage drops to a set value (eg 12.0V).
So far this has made a significant difference compared to our previous float charge routine that saw the house bank Voltages drop to 12.5V with minimal draws of even 50 Ah… Now, we are still above 12.1 V at ~50% SOC. I am also seeing better charge acceptance than before.
So far, this seems to have resuscitated the bank enough that my enthusiasm for converting to LiPO4 has been dampened for now. We will put that plan on hold for a few more years hopefully.
I'm not sure that a CC/CV charge routine could be implemented in your situation but the Firefly Manual does suggest that this is the optimal way to charge the FF.
As for the lower voltage tolerance of the various devices, I am reassured by your comments and my research into this question.
The one device in our collection of instruments that seems very sensitive to voltage drops is our Furuno TZTTouch2 MFD. (It will reboot intermittently when the thrusters engine start drop the house voltage.) I've also had some flakey behaviour from the NMEA 2000 GPS units that may be due to voltage drops; so, I put the MFD and all the NMEA 2000 instruments behind a Victron DC-DC converter that maintains a steady 13.2 VDC. Interestingly, I no longer see reboots of the MFD and so far no more extended periods of GPS 'no-fix' situations…
Anyways, I am glad to think that I can still use our Firefly bank for a while longer yet.
-evan
Thanks for these additional details on how you have adjusted your charging profile on your inverter/charger. As you know, in our use case we rarely have shore power so don’t usually use the charging capability of our three 240V Victron inverter/chargers and all our battery charging comes from the 14 MPPT controllers and/or the two Electrodyne alternators via their WakeSpeed 500 regulators. I’m still very glad that we went with individual MPPT controllers for each of our solar panels but it is a bit of a pain in this case as I have to go in and adjust each one individually so it is a bit tedious. Hence I’d like to figure out just what values to set the new parameters at to eliminate the constant Float charging and try to extend the life our 24 FF house bank batteries a bit longer.
Victron does not have the equipment of “Silent Mode” such as on your Magnus so I’m trying to figure out what settings I need to change to create a version of Silent Mode. I think it will probably involve changing the Tail Current setting as this is what triggers Absorb to stop and Float to begin but I need to do a bit more research to figure out if I can just sent the Tail Current to zero to disable it or if I need to use a different value. Perhaps I can even just set Float Voltage to zero and see if that might work. I’ll let you know what I figure out and if you have suggestions please do let me know. The Magnus installation guide was very well done and helped me understand better how they are using this Silent Mode so I’ll study that a bit more as well.
Like you, I too had good success initially with doing the Restoration Charge on our FF batteries and they recovered back to slightly more than the advertised capacity of 450Ah for each 4V cell. Unfortunately this only lasted for a few months before half of them again lost most of their capacity and I have not been able to get that back again. I am holding out hope that when we slow down our travels later this summer and I’m have the time and resources to work on this, I will be able to do a full and proper Restoration Charge and fingers crossed, recover the lost capacity a least somewhat as winter approaches. Like you, I’m hoping to be able to extend their lifespan as long as possible before I need to go through the considerable time and expense of replacing them with some completely different set of batteries.
For now the amble solar output is letting me nurse the existing batteries along with all systems onboard running just fine and as normal with no problems doing all our cooking which is electric, pumps, computers, navigation, etc. and should be able to do this somewhat indefinitely and so like you I’m not feeling quite the urgency to figure out what the longer term solution should be. I’m not likely to go with Lithium as our particular use case and the boat design just doesn’t get any benefit from the lower weight and higher energy features they have, and with so much solar and the alternators, fast charging isn’t any advantage so I don’t think the value proposition is there. But I still need to figure out just what batteries to go with between AGM and perhaps the GEL traction battiers but I’ll let you know as I work my way through that decion making process.
Re the low voltage situations, I did the same as you and installed a 70A Victron DC-DC 24V Orion that ensures that everything connected to that power supply gets a very clean and steady 24V output no matter what the input varies with such things as bow thrusters when they start up. Works very well and I’m a big fan of Victron’s DC-DC converters for many applications and have several onboard.
-Wayne
Perhaps this is too late being that you wrote this 9 months ago. This guy has a battery manager that very easily handles combined charging for a mixed lithium and AGM house bank.
It has been installed in some very large off grid residential but was designed to be installed on boats. It’s a about $500. He has at least a few videos demonstrating.
I have a small FireFly 465amp hr housebank and and may combine one additional lithium to it, he touts the advantages of combining.
https://youtu.be/XAOhT2HwKWM
Thanks for the link Tiemo, I’ll go check it out later today.
-Wayne