Battery Pioneer: Lead-Acid Is Key to Reducing Electric Car Battery Cost

By · August 14, 2012

Subhash Dhar of Energy Power Systems

Subhash Dhar of Energy Power Systems: If li-ion stalls, he's sitting pretty. (EPS photo)

Does Subhash Dhar know what he’s talking about when he says he knows the way forward with electric car batteries? Is he on to something when he says his company, Energy Power Systems (EPS), can make storage systems for battery EVs at a quarter their current cost?

Turbocharging Lead-Acid

Dhar’s breakthrough is not in building a better lithium-ion battery, in fact his solution doesn't use lithium at all. Instead, EPS is going back to basics with the technology that electric cars started out with at the beginning of the 20th century—lead-acid. Dhar says the company is adopting the lessons used in li-ion to vastly improve the efficiency of lead-acid.

There are good reasons to be skeptical about this, because EVs powered by lead-acid today are mostly short-range, low-power neighborhood vehicles. Lead-acid technology hasn't really improved all that much since the Detroit Electric was on the road in 1915.

But Dhar isn't saying that lead-acid alone will be viable in electric cars. Instead, he wants to combine the high energy density of li-ion with the power delivery of lead-acid—two battery types working together in one cost-effective pack. Again, he promises the same performance at considerably less cost. At $800 per kilowatt hour (an upper end estimate), a 30-kWh battery becomes a $15,000 cost to the manufacturer, which explains why you’re not getting into a LEAF for less than $30,000 (without government incentives).

Dhar's argument is based on the continued high cost of lithium-ion. “Look,” Dhar says. “the U.S. Advanced Battery Consortium (USABC) was formed in 1991, and its early grants helped ECD-Ovonics to commercialize nickel-metal-hydride technology. ABCD's aim was to get lithium-ion down to $150 per kilowatt-hour, and it was supposed to have been achieved by 1998. The energy density has improved, but we are still hard-pressed to find li-ion batteries today that are any less than $800 per kilowatt-hour. The fundamental problem is that the industry always goes for the glamor of watt-hours per kilogram, with not nearly as much attention paid to the cost of materials used in the technology.”

If Dhar is exaggerating the cost of lithium ion batteries to make his point, it's not by much. Leaders in the field, including Ford, Nissan, Pike Research, and Advanced Automotive Batteries all pinpoint the cost of finished installed EV battery packs between about $650 and $750 per kilowatt hour. Furthermore, these costs are expected to fall by about 10-percent every year for the next few years.

Dhar believes he can reduce costs further and faster by using the most venerable battery tech in the world, in cars before the 20th century dawned. “Lead is the cheapest material, and we’ve been using it in batteries for 165 years,” Dhar said. “But we haven’t made all that many improvements to it. So our thinking at EPS was to think out of the box and apply new learnings to old technology.” Read a three-part interview with Dhar to see if you find his arguments convincing.

I can’t prove that Dhar holds the magic formula, but he's worth listening to because of the man’s considerable experience in the field, as founding president at ECD-Ovonics (where he helped the legendary Stan Ovshinsky develop and market the now-standard nickel-metal-hydride battery), as president of Volvo supplier Ener1, and as chairman and CEO of Envia Systems—the company with the serious backing of the federal ARPA-E agency that says it is going to change the world.

It also bolsters Dhar's case that EPS’ board includes both Ken Baker, a pioneer who led the EV1 team at General Motors, and David Cole, one of the best-known auto industry interpreters and founder of the Center for Automotive Research (CAR).

Cole told me, "The key things are that the EPS battery will be about twice as energy dense as current lead/acid batteries. The company's batteries have low internal resistance, which makes them far better for taking power out and adding it back in than with lithium batteries. I think it is a great compliment to current technology."

EPS is confident enough about its technology that the Troy, Michigan-based company is talking about taking over a portion of Ford's Wixom, Mich. assembly plant, shuttered in 2007, to make its batteries. But so far the fledgling company lacks a website.

Increasing the Power

Dhar claims his company can delivery lead-acid batteries with greatly increased power without adding any cost back in or any tradeoff in energy density. Durability is also maintained, he said. The immediate market for these vastly cheaper batteries will be competing with companies like Johnson Controls to supply lead-acid batteries for micro-hybrids (storing the energy needed to power stop-start systems), full hybrids like the Prius, and mild hybrids such as the eAssist Buick LaCrosse.

The EV batteries will come later, Dhar says. He envisions cheaper battery solutions that combine the best of both worlds—high power from lead-acid and limited power but high energy density from li-ion.

The advanced lead-acid concept has moved beyond the planning stages, with engineering prototypes now under development. “Let’s start with a very low-cost material,” Dhar said. “As the Stan Ovshinsky used to say, you can’t fall out of bed if you’re already lying on the floor. Lead-acid can’t store as much energy as li-ion, but we’ve developed it to the point where it can deliver the power need by the LaCrosse and Prius.” OK, but as Dhar says of Envia, he has to prove his contentions. Neither company has yet shown off engineering mules with their batteries installed.

The bottom line, of course, is that if the li-ion battery stubbornly resists cost improvements, solutions like EPS’ will have to be considered. But li-ion companies, such as Dhar's former company, Envia Systems, aren't standing still. Envia says it's on the cusp of $20,000/300-mile EVs. If that happens, then EPS will be the patent holder on one more EV solution that never got out of the starting gate.


· Bret (not verified) · 5 years ago

The problem with lead-acid batteries is that they die every five years, usually without warning. Unless Mr. Dhar can solve that problem, people will be hating any EV that has a lead battery in it. I live at the beach and the Gem and Think golf carts are very popular here. The lead-acid batteries they use aren't popular.

Many of the NiMH battery packs from Rav 4s and Priuses have survived for over a decade and hundreds of thousands of miles. That kind of reliability is what future EV owners will expect from their cars. I believe nano-technology, like the cathodes and anodes developed by Envia, is the future for EV batteries. Toxic, caustic and failure-prone lead-acid is the past and I hope it stays there.

· Anonymous (not verified) · 5 years ago

Lead acid has lasted 10-15 years as a stationary storage if treated right. Part of the problem with using lead acid in EVs as the only storage method is that you tend to run them hard and below the depth of discharge they like. But if there is a way to keep the lead acid happy, then their life expectancy may increase considerably.

Nice thing about lead is that you know what you're getting into. WIth lithium ion, show me a 10 year old EV pack that is still in operation. We still just don't know what's going to happen with those batteries. I just hope they pan out.

· Streetcar Eddie (not verified) · 5 years ago

I think he has to pull a lead rabbit of his hat that solves the problems with traditional lead acid. The current technology would not be tolerated by the mordern day consumer with a room temeperature IQ.

· · 5 years ago

FWIW: the lead-acid battery in my previous gasoline car lasted 7 years, and the one in my current gasoline car is still the original and is 12 years old (I keep expecting it to fail any day now, but, not yet!).

· · 5 years ago

After reading this article, which brought up the association with Stan Ovshinsky, and another recent article here on Plug In Cars, where people with '90s vintage RAV4 EVs utilizing NiMH batteries were declaring that they're still doing quite well with them, I went online to review the history of that particular technology . . .

Interesting reading for all and especially required for those who still declare that Chevron never suppressed it for EV use.

There are other interesting battery formulas that you don't hear about all that often, such a nickel zinc, which seems to be touted by Powergenix as alternatives to NiMH in small household rechargeables (AA size, etc.) and in larger scale applications (computer UPS) as a replacement for lead acid . . .

Here at home, almost all the household gadgets have Sanyo Eneloop low-self-discharge NiMHs in them. Just about all the manufacturers make a low-self-discharge NiMH now. They're absolutely marvelous. I also have half a dozen PowerGenix NiZn AAs and, so far, they've also been great. I often think how well either of these would work scaled up and utilized in EVs. We know NiMH is a winner but NiZn could also be promising.

I'll have to read the 3 part interview linked in the article to learn more about Subhash Dahr's new generation lead acid cells. But I'm thinking that so much R&D has been going into lithium these past few years that iit will to be the dominant player in EVs for many years to come. Envia, in particular, looks very promising. Especially so after getting such glowing reviews from GM's CEO the other day . . .

· TexomaEV (not verified) · 5 years ago

Been combining Pb/Acid and LiFePO4 batteries together for a few years now. They work great together, both help to save each other during charging and discharging, and reduce the overall weight of the EV's battery pack. My latest hybrid pack can be seen in this EV. I also have a hybrid pack in my E-Riding Lawn Mower, as well as the battery bank for home solar/wind energy storage:

Experiment with the idea yourself, match up 4ea LiFePO4 cells & a 12volt Pb/acid battery, both of the same Ah capacity if possible, and see for yourself.

· SVL (not verified) · 5 years ago

I also read the Wikipedia article on NiMH again, and wasn't aware that the patents are no longer owned by Chevron. Wouldn't that make them more available for use in cars? Not sure, but I think it is something manufacturers should look in to, and if they have, I would like to know why they haven't opted to use them. The average EV hitting the market now with Li-ion has less range than the EV1 with NiMHs!

· Anonymous (not verified) · 5 years ago

HA - What is old is new again. This was done by GE in the late 60's with their DELTA electric car. I had the opportunity to hear the GM of that project Mr. Bruce Laumeister speak about it's development and how modern electric car makers still have not figured out that a mixed chemistry pack is key to acceleration and range. So much was lost between generations. Nice try Mr. Dhar but certainly not a revolutionary idea.

· · 5 years ago

"The average EV hitting the market now with Li-ion has less range than the EV1 with NiMHs!"

This is true, SVL, but the little EV1 was a 2-seater with impressive aerodynamics and barely enough cargo space to accommodate a small suitcase or couple bags of groceries. The Leaf, by comparison, seats 5 adults comfortably and has good sized cargo hold. If the Leaf was powered by NiMHs, something significant in the way of passenger or cargo accommodations would have to be sacrificed. Those older batteries, while a durable and proven technology, are heavier and bulkier. So, lithiums really are an advance over what we previously had and they're only going to get better.

What I'd really like to see is for one of the major manufacturers to introduce an EV1-like 2 seat runabout with nice lines and lots of lithiums . . . something with a 20 or 24kWh pack that really could get 120 miles or more on a single charge. So far, though, this sort of thing seems to be the sole province of do-it-yourself EV converters.

My concern, voiced of several topic threads here on Plug In Cars lately, is that some new EVs can barely be called an EV at all.
I'm not referring to the Leaf or iMiev or even the range extender Volt.I'm talking about bloated SUV-like vehicles that are either here already or promised to be here soon, with battery banks large enough to power 2 or 3 more sensibly-sized electric cars.

Worse, we'll also see Hummer-sized monstrosities with the aerodynamics of a cinder block, matched with increasing complex gasoline range extenders, increasing larger fuel tanks and resultantly smaller battery packs. Most people won't be buying these for the utility of a work truck or for hauling large and bulky cargo. They'll be using them to commute to work, with nobody in the passenger seats.

Because they'll be getting 17mpg instead of 7, they'll convince themselves they're saving money or helping the environment. The word "electric" will, no doubt, will be part of the car's branding and the owner can then tell everyone within earshot that they're driving an EV.

We'll then have something that I'll refer to as an EVINO . . . Electric Vehicle In Name Only. If this is the prevailing trend, we're then clearly headed in the wrong direction.

· · 5 years ago

@Benjamin - After reading your comment, I want to just drive my EVs off the side of a cliff in despair (no gasoline explosions will punctuate the demise). Without external pressure (much higher gasoline prices or some undeniable cataclysmic climatic event that is universally accepted as a result of climate change), we won't see a move in American consumer behavior in our lifetime. Most are averse to change and these EVINO vehicles will probably be with us for some time - just so larger vehicle consumers can continue with a vehicle that's "safe" and "roomy" (in quotes because those are marketing claims, not reality). And so the manufacturers can continue making good profits (they can't make as much profit on smaller more efficient vehicles). But, I'm still holding out for a gasoline price hike that will make my cycling safer and less noxious while my EVs become rare and sought after modes of transportation.

Regarding Lead EVs as a viable solution ... seems like a farfetched attention grabbing scheme. Yes they work, but not well in cold, are heavy, are dangerous (I have stains on my hands and holes in my clothes from handling those things), require more maintenance (at least the flooded versions do), and don't last very long. I'd have to see some convincing details to buy into an EV lead acid vision for the future.

· Anonymous (not verified) · 5 years ago

Cars collide with huge energy all the time. Lead is the last thing you want splattered all over the road.

· · 5 years ago

It is funny how I predicted and described that very same strategy years ago:
“Keep the patents in a safe until a year or two from the patent rights end date of 2014, then sell it out to a third party to generate doubt in car manufacturers minds about whether they should go to Lithium batteries or use the old now available NiMH. The doubt wins Chevron time and the final dispersion in decision increase the unit cost of both Lithium and NiMH batteries.”
A clear and perfectly orchestrated strategy. The only unknown was the third party Chevron would choose. Now we know it is BASF. A quiet clever choice of a foreign, innocent and not knowing third party. Job well done. If only they could be as effective in the good as they are in the bad, the world would be a much better place.

· · 5 years ago

Yeah, Dan, I guess I was in sort of a "gloom and doom" mode when I wrote that yesterday. Please don't drive off the edge of a cliff in you EV on my account!

I suppose EVINOs are going to be part of the mix and, as a member of a household that has a minivan (I like to refer to it as "my wife's car"), I guess I shouldn't complain too loudly about others driving outsized vehicles.

Even though the 2.5 weeks of borrowing a Leaf was a complete success (the owner returns to town today,) I know my wife will eventually replace the Mazda MPV with something that is still partially refueled by petroleum and larger than I would like. It will be up to me, when my '95 Saturn finally gives up the ghost, to replace it with a pure and somewhat small EV. I just hope such vehicles don't go out of style due to sluggish sales in 2012 and there will be at least one or two models to choose from.

· Mukesh (not verified) · 5 years ago

I don't know about solution of EPS/Envia for Lead Acid Batteries but we have a solution ! We are making MCF Batteries which work in PSOC, never sulphate, can work down to 100% DOD, have very low internal resistance, affordable and tested for Hybrid/EV application and last long! See our website . We are supplying these in limited quantities to actual users. A 30 Kwh pack with BMS should cost less than 10,000$ in quantity. Actual life can be in 10 years for such a pack with designed life of 15/20 years.

· Mukesh (not verified) · 5 years ago

The Advanced LA uses Micro Carbon Foam, MCF for making Grid of the battery plates. This gives high surface area and very good high utilization of the active material.

· · 3 years ago

The problem is not the battery/weight/cost, the problem is the car. Battery makers seem to forget that if they have a great system, a car needs to be built around it, not the other way around. For lead acid, I suggest a long, sleek, 2 seat commuter car with high styling, something like a 1960's Jaguar. A long nose can hold many batteries, along with stacking two rows of batteries behind the driver inside a GT fast back. Incl a small area inside behind seats for storage and be done with it. If the car has fantastic looks and a reasonable price it will sell soley based on its styling and functionality as a commuter car. Picture a very long, very sleek, cool, lead acid EV-1 type car.

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