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Firefly Energy Group BCI 31 Carbon-Foam Lead-Acid Battery Available for Testing 1Q 2008

The first pre-production versions of Firefly Energy’s new BCI Group 31 carbon-foam lead-acid truck battery (earlier post)—to be marketed under the new name “Oasis”—will be available for review and testing during the first quarter of 2008. Initial availability of the Oasis battery will be in the summer of 2008, with full production scheduled for the fourth quarter of 2008.

Battery Council International (BCI) provides standardized definitions for the physical dimensions of a wide variety of batteries, and the Group 31 size battery is a broadly-deployed battery type in trucks.

The Oasis battery will primarily be utilized when the truck’s diesel engine is turned off, and provide up to 50% longer run-times than competitors when powering accessories which collectively make up a truck’s hotel loads.

Firefly Energy’s Oasis battery will have a sealed valve-regulated design. The primary characteristic of the first Firefly Energy lead-acid battery is the inclusion of a high surface area, non-corrodible and light-weight carbon foam material.

Firefly Energy’s 3D carbon foam taps more of the power potential of lead acid chemistry which was impossible to unleash in the past with conventional designs. This technology not only reduces the lead content making the batteries smaller and lighter, but additionally enables faster, deeper and more reliable discharges and recharges. This significantly extends the battery’s life, makes it more environmentally friendly, and less expensive than lithium and nickel battery chemistries.

The company said conventional deep-cycle lead acid batteries used in trucking start showing sizeable performance drop-off after some 200 deep discharge cycles.

The Oasis battery will offer continuous power through the discharge process, a fast recharge to 100% capacity, excellent vibration resistance and greater cold-starting capabilities. Typical battery life is extended since sulfation is reduced.

When tested in cold weather extremes at minus 20°C, the batteries were capable of delivering above 65% of their rated “room temperature” capacity compared to 20% or less for standard Group 31 batteries. This can help minimize alternator damage incurred while attempting cold-weather engine starts when batteries are low.

Additionally, batteries with carbon foam electrodes instead of heavy lead plates are able to transfer heat out of the battery as rapidly as it is generated. Operating heat of the battery is lower, is also generated more uniformly, and is dissipated more rapidly, resulting in longer battery life in many applications.

Firefly Energy is unveiling the newly branded battery at the SAE Commercial Vehicle Engineering Congress and Exhibition (ComVec),  30 Oct. - 1 Nov. 1 in Rosemont, IL.



I wondered when this battery would show up in production; it may be the interim answer to the problem of producing low-cost batteries for BEVs. If the price of batteries is low enough, changing them out every few years wouldn't be a problem. The key: the price must be low!


Can someone tell the average consumer (me) how Firefly batteries may be advantageous over NiCad, NiMH or lead based designs?


Firefly batteries do not use expensive metals such as Lithium. Also, Firefly can use well understood techniques for manufacture.



Firefly is lead based. The chemistry is lead acid. The difference between other sealed, lead acid batteries, is the way in which the lead surface is available for the reversible chemical reaction to occur. Firefly uses lead coated graphite foam, rather than solid lead plates.

mpower has a good explanation of the difference in chemistries between lead acid and the other choices you mentioned.


So would this be competetive for hybrid applications or is it more for adding start/stop functionality to trucks? And does "trucks" mean pickups or 18 wheelers?


Well, duh it would be for whatever people want to use it for, so never mind. I'm guessing NiCad/NiMh would weigh less, too.

Michael McMillan

I remember they were initially harping 15000 deep discharge cycles. There is no mention of cycle life in the above info.

The initial advantage of firefly batteries was the low price. It was intended that the price per WH was to be 0.25 $US (last year). versus $3 minimum for lithium. The other advantages as to be the high cycle life and high availabilities of raw materials.

Their old propaganda said that the lead in a recycled battery could be made into at least 6 firefly batteries of equal or greater capacity.

-Michael McMillan


Yes, these batteries are good size... You wouldn't typically find them on anything smaller than the biggest of the full-size offerings from the big 3 (think F-450 and above) or in a big rig. IIRC, the Optima runs about 95 lbs vs. a Group 34 runs about 75 lbs. Group 34 are what you'll find in most light-duty trucks (think F-150 thru F-350), although they're starting to double up in the larger offerings.


Hi Michael,

From their October 3 press release;

While conventional deep-cycle lead acid batteries used in truck starting show sizeable performance drop-off after some 200 deep discharge cycles, the Firefly Energy battery is capable of achieving more than triple the deep cycles while still maintaining more than 90% of its initial capacity. I'd guess they can take ~700 deep cycles so the key questions are How much can the life be extended through battery management and What will they cost.


I can't imagine carbon foam would be all that pricey... Although it doesn't really behoove a corporation to make anything too inexpensive or last too long.

Roger Pham

What about the recycling aspect of this battery? Lead is toxic so recycling is a must. I suppose since lead melts at low temperature, and carbon is inert chemically at the melting point of lead in the absence of oxygen, the lead may simply be heated up until it melts and runs out of the foam?
Sounds promising, though. Hoping that further testing will uphold Firefly's promises.


I see that this is for trucks, wich is fine and all. But what about the cars? i mean it is about time , ok its overdue that we have something that is better for the environment and cheaper. But i dont see anything saying that this is for cars as well, so when does that come into the picture? and yes, im new to all this so if someone could explain this to me, that would be deeply apreciated! thank you!


I suspect they will make batteries for regular cars as well. Eventually. They seem to be focused on a pretty heavy duty battery for now. These first batteries should be available for sale in 2009. Hopefully, much of the testing they do with the heavy duty batteries will shorten the time it takes to bring car batteries to the market.

Rafael Seidl

@ Elliot -

the article talks about hotel loads, i.e. cabin heater and lighting in an HDV cab. The technology would make sense in passenger cars too, e.g. to equip diesel or large gasoline engines with reliable start-stop functionality even in severe winter weather. Another application would be as a power source for a block heater, if a grid outlet is not available. Finally, a small inverter would permit 110 - 240VAC household devices (depending on country) to be connected, e.g. for outdoor recreational use.


IMHO They are addressing one remaining problem with high energy density batteries, the cost.



If the technology is successful it could eventually go into cars. The alternator in your car maintains your battery in a state of full-charge. If you let your car sit for a long time, or if your alternator doesn't work, your battery will discharge until you can't start your car. The discharge over time is called "self-discharge." All batteries have it to some extent -- lead acid and NiMH are among the worst; lithium is one of the best.

A key feature of the Firefly battery is that it can deep discharge many times without damaging the battery. When a truck driver stops for a rest he can heat his little cabin while he sleeps, and maybe watch a little TV. To do this without running that big diesel engine he has to discharge his battery. Conventional lead acid is horrible for this because they can't be discharged very many times. So a Firefly battery can sell for a premium for that application. If they can ramp production to higher volume, and thus reduce the cost, then it could conceivably be used for cars. That would save some weight, which saves fuel.


Reticulated Vitreous Carbon isn't new - it was invented in the 60s. Phil Ross was using it on ZnAir in the early 90s. It really is not an earth shattering idea to use a lighweight substrate plated with the Pb or Pb/Sn as Power Technology Corp have done well before Firefly got the limelight. Gives increased surface area to volume ratio, hence more power capability and greater total energy capacity. I think the RVC is formed by a high temperature process so either you could perhaps melt the lead out or strip it out electrolytically, by a deep discharge.

Remember most of the lead mined in the world goes into PbA batteries and nearly half the lead produced each year comes from recycled PbA batteries - its a huge industry. Life is really the only thing stopping use of PbA in EVs - if Firefly and Power Technology Corp batteries can give us over 50Wh/kg then being so much cheaper than NiMH even a 2 year life becomes affordable.



Recycling rate of lead-acid batteries in US is 98%. Increased production of lead (and reduced per cent of recycled metal in new batteries) is due to increased demand from China, India, and other rapidly developing countries.


Very impressive and welcome substract foam technology.
I think necessary more information about how thermal runaway can react or affect carbon foam lead acid battery to the sealed VRLA versions.

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