FireFly Carbon Foam Batteries

[MichiganBill]

HI, First post so pardon me if any format errors. Does anyone have any experience with FireFly carbon foam batteries? In the fall we are going to be doing a trip where will need more amp-hours than the marine deep cycle / starting battery the dealer installed will handle. I've been doing some research and came across the FireFly battery. What I understand: Was developed by Caterpillar for heavy equipment that had long periods sitting with no use. Has been in use in HD equipment world for about 10 years, in Marine usage for several years. Similar to AGM batteries except carbon foam replaces the lead plates. Stated advantages over AGM: 1) can cycle down to about 80% discharge without damage or too low of voltage so more useable amp-hours for same size. 2) Does not sulfate readily so has longer life (several orders of magnitude per claim). 3) very low self discharge when not in use. Compared to Li; 1) lower costs 2) can handle low temperatures and still discharge and charge. Disadvantages: a) more costly per battery than AGM BUT for my Amp-hour needs I can buy only one, with AGM I would need 2 so about same costs. b) Not a huge number of units sold and in use for many years to validate the long life claim. I consulted a friend that has been in the ocean going boat service business for years. He is a fan. I'm wondering if anyone in MOC has experience with FireFly Batteries. I've been an engineer too many years to put much faith in data on a sales website.

[Chalkie]

All I have to say to you sir is this: "You must be rolling in greenbacks!" I looked up their prices and while I do not consider myself rich, I certainly can afford to buy NECCESSARY items, and this certainly NOT one of them in MY timeline.

[MichiganBill]

Hi Chalkie, The FireFly is more money than AGM but a lot less than Li Ion. For my amp-hour needs while off the grid I can get by with one Firefly but would need two AGMs. A local dealer quoted me both for the FireFly and 2 good AGMs. The Firefly solution is about $50 more than the AGM solution. IF the claim of 3 to 4 times the life is even close to true I am way ahead with the Firefly. Plus 70# less of battery to carry around. I'm not printing greenbacks so I might just do the least expensive solution of a couple of 6 volt flooded batteries and worry about it later in a few years. Right now just trying to find out as much as I can before I decide.

[RipNC]

I replaced my house bank on our boat with 2 - Firefly carbon foam batteries, primary reason was more usable amp hours. I didn't feel LiFePO was ready for use on my boat (maybe larger boats).

I recently replaced the batteries in our 2021 3121RL with LiFePO for same reason but also for weight savings. Now have 618 Ahrs in our rig. The Fireflys have been great on the boat. However, each of my three 206 Ahr 48 lb batteries in the rig weigh less than 1 Firefly at 74 lbs and 116 Ahrs.

[RipNC]

Also, Capital cost per usable amp hour was about $6 for Firefly and $5 for the SOK batteries. Based on 80% discharge for Firefly and 100% for LiFePO (max discharge for each chemistry). I paid $560 each for Firefly (shipped) and $1,028 each for SOK (shipped). Very happy with both in their installed applications.

A $235 amp hour AGM at 98 Ahr and 50% max discharge is about $4.80 per usable Ahr.

The SOK is now available in a plastic case and might even be a good marine battery now...

[jcurtis934]

Great to have real life data from an actual user. My group 31 agm batteries work for me and when i have to hoist in new ones, i will consider it exercise while i mutter some strong language. Thanks for giving us some education...much appreciated!

[RipNC]

You're welcome.

BTW - When you really analyze the data it goes much more in favor of LiFePO4 because of the number of charge cycles the battery can take. LiFePO4 estimated at 3,000 cycles at 100%, carbon foam 1,000-1,300 at 80% and a good AGM is around 1,000 at 50%. All these battery chemistries will have a longer life and more charge cycles at lower depth of discharge rates.

Wet cell lead acid are all over the map with prices anx capacities, but they do well in most complete analysis, until yo factor weight (a whole nother layer of analysis).

[Tom0329]

Buy boat batteries for a boat. AGM is junk. LiFePO4 batteries will out preform any lead acid batteries. And the price is coming down. Some come with battery management systems with low temperature cutoff.

[RipNC]

Tom0329

A couple points:
OP asked about Firefly batteries, I used them for marine use (in my boat) but the carbom foam battery was invented at Caterpilllar after they took flack for lousy batteries they branded and sold with tbeir equipment.

As my qick analysis in prior posts shows, you're correct - LiFePO4 is the winner when you look long term.

The SOK 206 Ahr (x3) in my 3121RL have BMS w/low temp cutoff.

Not sure I'd agree with AGM being junk - I've used a number of them in my prior boats, especially in tough to get to compartments where topping off wet cells would have been a PITA.

Lastly the line between Marine and RV is getting more blurred everyday, case in point Battle Born Battery markets to both segments very aggressively.

[Tom0329]

AGM and Firefly batteries are made for starting machinery. That is a fast outrush of current. Expecting dependable power or longevity from either of those types will be disappointing.
I the long run lithium chemistry is the best bang for the buck.
Battle born batteries have very good marketing strategie . However there are better choices on the market. Battle born does not have low temperature cutoff. Others do.

[RipNC]

Don't believe that is entirely true, BB cutoff for charging is 24 F (internal cell temp) and will continue to discharge down to -4 F. For the record- I'm not a BB fan myself (I bought SOK).

Also, Firefly batteries are most certainly deep cycle batteries as are many brands of AGM batteries.

[Creeker]

Originally Posted by Tom0329

AGM and Firefly batteries are made for starting machinery. That is a fast outrush of current. Expecting dependable power or longevity from either of those types will be disappointing.
I the long run lithium chemistry is the best bang for the buck.
Battle born batteries have very good marketing strategie . However there are better choices on the market. Battle born does not have low temperature cutoff. Others do.

Baloney! Lead Acid GC2s and AGM's are very good choices for the huge majority of RVers. Thousands have been using them for decades and totally satisfied. I'm among them.

Best bang for the buck?

2 Lead acid GC2's - Deka GC25 235AH $135 x 2= $270 for 117Ahs.
1 Battle Born 100 AH - $950.00 for 100Ahs

Longevity? You had your Lithium batteries for 10 years in an RV application? No and neither has anyone else. I know for fact GC2's will last me 6 to 7 years. Done it over and over again.

I have no doubt Lithium will outperform LA and AGM in every way. They are also much lighter. But these guys pushing this best buy in the long run stuff is pure baloney! They have no idea how long their batteries will last in an RV application. No one does.

The only thing we know for certain right now about cost is lithium is 3+ times the cost of old reliable GC2s. Give it 10 years and we'll know.

[RipNC]

Creeker,
A friend installed early generation lithium in his boat 8 years ago and hthey are still going strong powering 2 Victeon Multiplus that produce 220v for the 22 cubic foot residential fridge and the electric range and oven. They anchored out alot and were even able to run the small A/C in the master stateroom.

I agree (and said so) that lead acid fares well in any analysis, however not so when you factor weight/usable Ahr. My LiFePO4 provide over 600 usable Ahrs weighing in at 150 lbs. 12 Trojan T105s weighing in at about 750 lbs will provide 675 usable Ahrs (5x weight for about 10% more Ahrs).