Carbon Foam Batteries? (VRLA AGM GEL)

ligwydligwyd Registered Users Posts: 169 ✭✭
edited August 2020 in New Battery Technologies #1
Hi all,
Just came across these batteries and wanted to get some feedback from the forum?

Claim to fame is 13500 to 16500 cycles at 30% DOD and can stay at 50% DOD for a long time with not negative effect. Sealed and pretty much maint free.

As far as the specs go, looks like an interesting product.

Anyone have any experience with these or care to comment and discuss?


  • Graham ParkinsonGraham Parkinson Registered Users Posts: 70 ✭✭
    Very popular with the sailing cruiser crowd but quite expensive.  Go to and search on Firefly.

    I didn't know they came in 2V and L16 formats.  Our electrician has told us that he is recommending carbon batteries now on all his off grid solar projects.

    Battery U says this about Lead-Carbon cells:

    Advanced Lead-carbon

    Scientists have known for years that sulfate accumulation prevents the classic lead acid from delivering sustained performance; partial charge and aging are the main culprits because the negative lead plate is not sufficiently scrubbed. The advanced lead-carbon (ALC) solves this by adding carbon to the negative plate (cathode). This turns the battery into a quasi-asymmetric supercapacitor to improve charge and discharge performance.

    Figure 1 illustrates the classic lead acid cell with the lead negative plate being replaced with a carbon electrode to benefit from the qualities of a supercapacitor.

    Advanced Lead Carbon
    Figure 1: The classic lead acid develops into an advanced lead-carbon battery.
    The negative plate is replaced with a carbon electrode that shares the qualities of a supercapacitor.
    Courtesy of Advanced Lead-Acid Battery Consortium (ALABC)

    The ALC is being tested as a replacement for the classic starter battery in start-stop applications and in 48V micro and mild hybrid systems. Rapid charging on regenerative breaking is a decisive advantage with these batteries, a task that is difficult to achieve with regular lead acid. Although larger and heavier than Li-ion, the ALC is low-cost, operates at subfreezing temperatures and does not need active cooling — advantages Li-ion cannot claim. Unlike regular lead acid, lead carbon can operate between 30 and 70 percent state-of-charge without fear of becoming sulfated. The ALC is said to outlive the regular lead acid battery, but the negative is a rapid voltage drop on discharge, resembling that of a supercapacitor.


    Firefly Energy

    The composite plate material of the Firefly Energy battery is based on a lead-acid variant, and the maker claims that the battery is lighter, longer living and offers a higher active material utilization than current lead acid systems. It is also one of the few lead acid batteries that can operate for extended time in partial-states-of-charge. The battery includes carbon-foam electrodes for the negative plates, which gives it a performance that is comparable to NiMH but at lower manufacturing costs. Firefly Energy was a spin-off of Caterpillar, and in 2010 it went into bankruptcy. The company was later revived under separate ownership but folded again. Since 2014, the battery is manufactured in India under Firefly Batteries Pvt. Ltd.

    Offgrid in cloudy PNW

    MacGyver'ed museum collection of panels, castoff batteries and generators - ready for state of art system install ....

  • Marc KurthMarc Kurth Solar Expert Posts: 844 ✭✭✭✭
    There has been a lot of sales hype on these for years, but very little solid info from the field. Even the comparison tests that I have seen were slanted because they were not conducted in accordance with each manufacturer's required charging parameters. It is difficult to develop an informed opinion without more information in real-life applications. After so many years in the field, there seems to be a lack of hard field data.
    I suspect that the carbon-composite design offers some incremental improvement over many conventional lead-acid batteries in regards to sulfation when the batteries are abused. Beyond that? Time will tell.
    I always have more questions than answers. That's the nature of life.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,908 ✭✭✭✭✭
    Steve Higgins of Surrette has shown evidence of their flooded battery with carbon materials having a measurable performance increase. They started testing 5 years ago and have been on the market over a year now.

    I wonder if the hype here is being mixed up with AGM ?  Full River and Concorde are not using carbon yet, I believe?

    US Battery is also working on their line and it has my attention for clients.

    U.S. Battery Evaluates Expanding Market Reach Based on Gridtential Energy Silicon Joule™ Technology

     Santa Clara and Corona, Calif.-Gridtential Energy, the inventor of Silicon Joule™ bipolar battery technology and US Battery, a global leader of FLA (flooded lead acid) deep cycle batteries, announce that they have entered into a formal agreement to collaborate on Silicon Joule™ bipolar battery technology.

    Under the terms of the agreement, US Battery and Gridtential Energy will industrialize bipolar plate pasting and curing processes. Additionally, Silicon Joule™ bipolar AGM (absorptive glass mat) batteries will be assembled and tested, using US Battery active material to drive further improvements in cycle life, energy density, battery efficiency, charging rates and manufacturability. As US Battery achieves new performance milestones, the company will be well positioned to manufacture and distribute industry leading bipolar AGM products to the market.
    Silicon Joule™ bipolar technology enables an innovative class of advanced lead batteries with silicon at its core. It is a design driven, low-cost, high-performance, patented energy storage solution that provides improved power density, cycle life, dynamic charge acceptance and wider temperature range, with up to 40% lower weight, while retaining full lead-battery recyclability. This is all accomplished while leveraging existing technologies from mature industry supply chains – allowing rapid scaling through existing lead-battery infrastructure.
    US Battery provides FLA and AGM deep cycle batteries for golf cars, NEV (neighborhood EV) & LSEV (low speed EV), industrial electric vehicles, as well as renewable energy & energy storage battery markets. US Battery products provide premium deep cycle battery life with the advantages of high initial capacity, fast cycle up to full rated capacity, high total energy throughput, ultimate charger compatibility, and high charge efficiency to meet new regulatory requirements at low cost per watt-hour.

    Terry Agrelius, CEO of US Battery commented, “US Battery hopes to combine the current advantages of premium deep cycle, lead acid battery cycle life that provides low cost per watt-hour over the life of the battery with the advantages of high power density and increased cycle life offered by the Gridtential Energy Silicon Joule™ bipolar battery technology. This combination could provide the improvements necessary for US Battery to better compete with the advanced battery technologies currently on the market and proposed for future market development while maintaining the safety and recyclability of lead based battery technologies.

    John Barton, CEO, Gridtential Energy said, “US Battery is an ideal partner for Gridtential. Leapfrog product innovation often starts with fresh thinking on how to best utilize core company strengths to make a disruptive move. Gridtential offers a better way to build a battery with modern materials from the solar industry. The leadership at US Battery is taking a smart approach, leveraging Silicon Joule™ technology with their organizational expertise in electrochemistry and battery manufacturing to create a new class of high performance products. Gridtential is proud to work with partners taking bold steps to accelerate advancements in the industry.”
    About Gridtential Energy
    Gridtential's cutting-edge Silicon Joule™ battery architecture combines the traditional benefits of lead batteries – low cost, near 100% recyclability, and safety – with the performance and life cycle usually associated with lithium batteries. Industries from motive power to grid energy storage are searching for lower-cost, sustainable solutions to meet diverse energy needs.
    Gridtential Energy provides Silicon Joule™ reference batteries, development kits, bipolar materials and non-exclusive licenses, enabling manufacturing partners to easily adapt their factories to provide high performing, higher voltage 24V & 48V batteries to their customers for the hybrid-automotive, Low-Speed EV (LSEV), energy storage system (ESS) & Telecom back-up markets - all without giga-scale capital investments. To learn more visit:
    About US Battery
    U.S. Battery Mfg. is the industry leader in manufacturing deep cycle batteries designed for: solar power, renewable energy, wind power, energy storage, golf car batteries, marine & RV batteries, scissor lift batteries, sweeper batteries, scrubber batteries, automotive, and most other uses for deep cycle batteries. U.S. Battery Mfg. has been building flooded lead acid batteries since 1926, and its American made batteries are the best quality longest lasting most dependable Energy Storage batteries manufactured - guaranteed. U.S. Battery continues to push the boundaries of battery power and in the process, is being recognized as the most respected deep-cycle battery manufacturer in the industry. US Battery operates battery manufacturing plants in Corona, CA, Augusta, GA, and Evans, GA. For more information visit:


    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

  • Marc KurthMarc Kurth Solar Expert Posts: 844 ✭✭✭✭
    Dave, No on Concorde or Fullriver USA.
    I am all ears when folks have some real data to share from field deployment, but glittering generalities are more readily available than hard data. I have a lot of old off-grid AGM battery banks running out there, so my opinions have been formed based on what I have learned in the process.
    I always have more questions than answers. That's the nature of life.
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,908 ✭✭✭✭✭
    Me too!  When I see it in the store here, from folks like you, or my suppliers, I then think about it for 6 more months.

    Otherwise it is like the shirt below, my favorite. Call anytime!  Do anything you wanna do!

    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

  • Dave AngeliniDave Angelini Solar Expert Posts: 5,908 ✭✭✭✭✭
    edited February 24 #7
    My soft spot is for them! Saw them in 1977 when Bon was the man!

    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

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