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!
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?
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!