The reason for Dhar's approach is simple: Improvements in power density and cycle life can be realized cost effectively. A small, 1.5-kWh lead-acid battery can adequately power a hybrid, while cutting costs by 50 percent, Dhar said. He ultimately hopes to be able to match the power density of nickel-metal hydride chemistries (which are used in 95 percent of hybrids) at one third their cost.
The company's concept doesn't end there, however. Dhar believes EPS can use its lead-acid technology in plug-in hybrids by teaming it with a small lithium-ion battery. In this scheme, the small lithium-ion battery would handle the energy (range) issues, while the lead-acid battery would provide the power. As an example, Dhar says he could replace the 16-kWh lithium-ion battery in the Chevy Volt with a 3.5-kWh lead-acid battery and a 9-kWh lithium-ion pack. Doing so, he believes EPS could cut the battery pack cost of a Chevy Volt from approximately $12,800 to under $6,000.
In essence, Dhar's concept boils down to a simple idea: At $100/kWh, lead-acid costs about one seventh of what today's liquid-cooled, lithium-ion battery packs cost. Moreover, lead-acid has been around for a century and is well understood by engineers.
EPS is reportedly working out a development plan with the state of Michigan and hopes to set up manufacturing facilities in an old Ford assembly plant in Wixom, Mich., by 2014.
With the auto industry scrambling to find a better battery for electric cars, Dhar believes the timing is right for his company's concept:
The industry discarded lead-acid chemistry a long time ago because it didn't have the energy density for electric vehicles. But we think it's time for a paradigm shift. We need to start thinking about how to improve miles per gallon by combining combustion with electrons. Once you do that, it lowers the amount of kilowatt-hours that you need.
Hey Charles... i had thought about what Jerry is proposing... that lower output batteries might be the answer, I just didn't think that those would be that much cheaper per kwh...
As for cost we have been buying EV size lithium cells for $450/kwhr for a couple yrs retail so I don't expect it's costing GM even that. Add $100/kwhr for making it into a pack and BMS and you are at $550/kwhr.
But the claim here was reduction from $800/kwh so that's the starting point of the GM Volt's batteries right now.
Anyway, I can see where using a lead-acid battery to apply some punch at the starting block and then drawing slow and steady from the Li cells might be a good way to go.
oldtimer, the biggest problem is charging and balancing the cells thus the life of them. Most batteries don't die, they are murdered by over, undercharging or over discharging them. Sadly for the Bolder it wasn't very good at that.
You are right a big secret for not just lead batteries is low resistance interconnents and the paths to them from the active material. This cuts heat which causes most of lead batteries problems when not designed right/too cheap.
All lead batteries when fast charging, assuming good design, actually cool down until the 80%charge/gassing level. And don't slow down and even Bolders can explode. So while they like most lead batteries can charge as fast as they discharge, you have to be careful in the last 20%.
The Bolder or A123 are far superior to UC's in so many ways at a couple % of the UC's cost. Whenever I hear, read someone touting UC's I either see a con or gulible person as just not practical. Same about foolcells too.
Most of the weight in a Lead Acid battery is the in the lead grid that supports the active chemicals. Firefly Energy tried to solve the weight problem by replacing the lead grid with a support made from carbon foam. They didn't succeed. I'm not sure of the reason. It might have been technical or it may have been the money ran out before all the details were worked out. They were a technology spinoff from Caterpillar Corp. They started out in Illinois and got a fair amount of support from private and government funding but still went belly up. A company in India bought the technology and as far as I know is still working to develop it.
RalphyBoy, the answer to your question is below. The answer comes by e-mail from Subhash Dhar, CEO of Energy Power Systems. Note that Dhar cites the diminished need for thermal management. As we've reported many times, the National Academy of Engineering has estimated that about half the cost of today's lithium-ion battery packs lies in the packaging and thermal management system. Dhar is suggesting that some of that cost would be eliminated. See below.
Here is Dhar's response to your question:
"The Volt battery is designed for power and energy; it is assembled using three cells of 15 AH each in parallel to achieve 45 AH capacity; it also uses higher expensive conductive components to achieve power.
"In our hybrid battery the Li-Ion battery will not have parallel cells; these cells will be high energy cells without the need for higher power capability, which adds significant cost for thermal management.
"So the fewer number of higher capacity cells that do not have to deliver high power cost significantly less."
Gas / Lithium / Lead. I like it. It's a complicated problem we have, and I don't think there's a simple solution.
Charles, you could have titled your article "All that was old will be new again".
One poster said no one needs a car that goes 0-60 in 4 seconds and has a 300 mile range. I don't know who would give up a 300 mile range. If EVs / hybrids are going to be viable, they have to give us something close to what we have now.
A bold, gold, open-air coupe may not be the ticket to automotive nirvana for every consumer, but Lexus’ LF-C2 concept car certainly turned heads at the recent Los Angeles Auto Show. What’s more, it may provide a glimpse of the luxury automaker’s future.
A half century ago, cars were still built by people, not robots. Even on some of the country’s longest assembly lines, human workers installed windows, doors, hoods, engines, windshields, and batteries, with no robotic aid.
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