a conversation with
Senior Vice President
By Noel Adams
Firefly Energy’s Ed
Williams and Mil Ovan test an all-electric mower, battery test array
(mouseover) Two equivalent 2-volt battery cells; left is classic lead acid, right is Firefly Energy graphite foam.
In 1859, Gaston Plante, in France, developed the first practical rechargeable battery. His battery remained a laboratory curiosity for twenty years until it was improved by another Frenchman, Camille Fauve. The battery that Fauve developed is basically the same as the flooded cell lead acid battery used today in millions of applications. The next big improvement didn’t occur until 1957 when a German called Otto Jache patented the valve regulated lead acid (VRLA) battery, sometimes known as the sealed lead acid (SLA) battery.
In recent years, battery development has focused on new battery chemistries that have been able to deliver significant advantages over the lowly lead acid battery in terms of both the number of recharge cycles the battery can survive, called the batteries cycle life, and the energy density of the battery, usually specified in watt hours per kilogram or Whr/Kg. Energy density is measured at room temperature for a slow discharge over a period such as 20 hours. The problem is that while these new chemistries deliver significant improvements in energy density and cycle life they are much more expensive than lead acid batteries.
The people at Firefly Battery think that they can change this. They have developed a battery using lead acid chemistry that significantly increases the power density while improving cycle life. Lead acid battery chemistry is theoretically capable of delivering 216.8 Whr/Kg while current technology averages 30 Whr/Kg. I talked with Mil Ovan, Senior Vice President of Firefly Energy, about this battery and their future plans.
“It all started because Caterpillar had a problem with current technology lead acid batteries”, Mil told me. “Caterpillar, who makes heavy earth moving equipment, found that their vehicles were plagued with battery failures. Batteries had to work in environments of extreme hot and cold temperatures, tremendous vibrations, and long periods when the batteries weren’t used, and current lead acid technology wasn’t always up to the task. Caterpillar, which spends between seven hundred and nine hundred million dollars a year on R&D, turned to Kurt Kelly, one of their materials scientists, who is now senior scientist at Firefly Energy. He was asked to build a better battery.
Kurt, who had never worked with batteries before, started by taking batteries apart and found that the lead plates in these batteries were failing often due to corrosion on the positive plate and sulfation on the negative plate. Kurt was walking down the hallway one day and saw a group of his co-workers examining some graphite foam that they were investigating for use in radiators. A light bulb went off in his head – he could make that graphite foam work in a grid. This became the base of the firefly battery. It allowed an increase in surface area while reducing weight and the amount of lead needed for the battery. In other words much higher energy density. The increased area also means the batteries will except and disperse power faster than traditional lead acid batteries. Caterpillar established Firefly to further develop and market these new batteries.”
I asked Mil about the cycle life of these batteries. He told me “cycle testing is still in progress so we don’t have a definitive answer right now. It takes a long time since there are only so many charge discharge cycles you can do in a day. We were expecting these batteries to perform slightly short of NiMH and Lithium batteries but so far we are doing better than expected, tracking very closely to the cycle life of NiMH”.
In preparation for the interview I reviewed the Firefly Energy web site and saw that their first customer would be Electrolux. I asked Mil about this.
“What do you think about when you hear the name Electrolux?” Mil asked. “Vacuum cleaners” I responded thinking about my Mum’s old Electrolux cylinder vacuum.
“That’s what most people think” said Mil “but Electolux also owns companies like Husqvarna, Poulan, and Weed Eater which build garden tools. The ride-on mowers you see at Sears Garden Centers are most likely built by Electrolux. Their problem was that garden maintenance tends to be seasonal. People maintain the lawn during the spring and summer then put the equipment away in the fall until next spring. They park the lawn tractor with an empty battery and when they come to use it again after several months the battery is dead due to sulfation.
The Firefly battery’s construction makes it very resistant to damage by sulfation. In our testing we fully discharged the battery and let it sit for a week in a bath at seventy degrees Centigrade to speed up sulfation. When we do this with our leading competitors they typically recharge back to about eighty percent of capacity. Our batteries come back to one hundred percent capacity. We brought Electrolux in under a non-disclosure agreement and they got very excited about the batteries. They have invested in Firefly Energy and will become the first customer for the batteries.
We also brought in the British aerospace company BAE, under non-disclosure agreement, and they too invested in the company.”
I inquired when they would start production and Mil told me “it will be some time next year”.
My next question was, “Have you tested the batteries in packs to see how if they can provide enough current for EV and Hybrid vehicle use”.
Mil answered, “We are doing progressive testing starting out with small packs and have not yet progressed to larger packs. We are confident that our batteries will exceed what packs using the current Lead Acid technology provide. We have been in talks with several automotive companies about our batteries but I can’t say which just yet.”
I asked Mil if they would consider making these batteries available in small quantities to EV owners. He responded, “We will be looking at niche markets but we have to focus on that are going to give us the biggest bang for the buck. We have to make the batteries profitable and right now that means focusing on Electrolux.”
Mil had only a little time available and would have to leave in a few minutes so my last question was “how much?”
Mil answered, “We are expecting the price to be in the range of one hundred to one hundred and fifty dollars per kilowatt, slightly higher than current lead acid batteries but much less than NiMH or Lithium batteries.”
The new Firefly batteries, if they live up to their promise, could be the major breakthrough that EV proponents have been expecting for the last thirty years. These batteries appear to offer the performance and cycle life of NiCad, NiMH, and Li Ion batteries without the associated astronomical cost. I haven’t been able to tie Mil down to a figure on energy density but he expects it to be two to three times the current energy density of current lead acid batteries. This would put them close to NiMH at 70 whr/kg but lower than Lithium at 120 whr/kg.
To illustrate the potential for these batteries let’s look at three cases that would benefit from them.
The plug in hybrid (PHEV), is currently viewed as the next best step toward reducing dependence on foreign oil and reducing CO2 emissions. Using the firefly battery you could build a thirty mile range PHEV with a battery pack costing no more than the cost of the current Prius NiMH pack.
The cost of the battery pack for a full function EV like the RAV4-EV would drop from close to twenty thousand dollars down to a range of five to six thousand dollars.
The weight reduction would allow Global Electric Motor Cars to make their six seat utility NEV street legal, by dropping the weight below the limit set by low speed vehicle legislation, without making the vehicle cost prohibitive.
Since both Nickel and Lithium are found in limited locations around the world, there is the threat that moving to an energy model based on Nickel or Lithium batteries will just trading the petroleum producers with another group of foreign suppliers. Lead is also much cheaper than either Nickel or Lithium and is obtained from a much more diverse group of countries.
It seems like a win-win situation and I will be watching developments with bated breath.
Since my conversation with Mil Ovan, Firefly have announced that the defense bill for fiscal year 2006 includes 2.5 million dollars to speed up development of the Firefly battery.