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Details on Valence batteries in EnergyCS version of PRIUS+
Mar 22, 2005 (From the CalCars-News archive)
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While CalCars is getting closer to upgrading our lead-acid PRIUS+ with a nickel-metal hydride pack, EnergyCS has moved ahead with a lithium pack, using Valence batteries that are described in the excerpted article that follows.

It's a Premium Article in the current issue of EVWorld: full text and 28-minute 6.88MB downloadable interview are available to subscribers at $29/year -- well worth supporting! You can find other links to Valence, previous EVWorld story on EnergyCS's version of PRIUS+, etc. at http://www.calcars.org/­vehicles.html .

http://www.evworld.com/­view.cfm?section=article&storyid=825
Valence Technologies On A Roll
Interview with Dean Bogues, VP of Sales and Marketing and Marc Kohler,
manager of electric vehicle market development at Valence Technologies.
By Bill Moore
March 18, 2005

PHOTO CAPTION: Valence's Marc Kohler with Energy CS's 150 mpg Prius plug-in hybrid. Valence Saphion (tm) lithium-ion batteries were installed in place of the Prius' 1kWh NiMH battery pack, which is located under the rear passenger seat. The car is a proof-of-concept prototype, which will make its official debut at the 21st Electric Vehicle Symposium in Monaco next month. The plug-in hybrid concept lets the car run further on electricity stored from the electric power grid instead of gasoline for the first 50-60 miles, effectively tripling the miles per gallon performance of the car.

It seems that lately I can't conduct an interview without bumping into Valence; if not their people, their product.


<snip>
It seems Segway was so impressed with the safety and energy density of the Saphion battery that they are offering it as an option in two of their new models.

What's that do for the self-balancing, two-wheeled people mover? Only doubles its range and probably doubles its life cycle. (Watch for that interview in the near future).

A couple weeks before this, I was in Los Angeles, Monrovia to be precise, visiting Energy CS about their exciting new plug-in Prius, which is now equipped with Saphion(tm) batteries. While I am admiring the set-up, in walks Marc Kohler, who is one of the two people you'll hear from during this interview, along with Dean Bogues, Valence's vice president of Sales and Marketing.

Clearly these folks have something exciting in a transportation-tailored electric/hybrid-electric vehicle battery.

Founded in Austin, Texas in 1989, the company manufactures a wide range of rechargeable lithium chemistry batteries. Though it has the capability of producing lithium polymer cells, it currently focuses much of its attention on lithium ion cells in either cylindrical, prismatic or vacuum-packed configurations, including both small format (mobile phone) up to large format cells, which are targeted for the needs of series hybrids (buses, typically), plug-in hybrids (a newly emerging technology) and pure battery electric vehicles like the sexy Venturi Fetish.

Besides the company's headquarters in Austin, it has a small test facility in Henderson, Nevada, outside Las Vegas, plus three facilities in China; one of which is devoted to research and two manufacturing plants.

No Lava Flow Batteries Here

One of the first issues I wanted Valence to address is that of safety. Two recent developments would seem, on the surface, to have a negative impact on their business, but in fact, turn out to be more a plus than a minus.

Many lithium chemistry batteries use a cobalt oxide, which gives a very high energy density, but can be prone to a potentially dangerous phenomenon called "thermal runaway". Either because of a manufacturing defect or mishap with the battery, the oxide can heat up and begin to burn at 700 degree Centigrade or 1,200 degree F, which Bogues pointed out is the same temperature of volcanic lava. Because of this, the US federal government now restricts shipment of lithium batteries in the cargo hold of commercial jetliners, though they can still be shipped by dedicated air freight carriers.

Because Valence uses a different chemistry in their proprietary "Saphion" batteries, their batteries will not catch fire. The trade-off is slightly less energy density, but a company like Segway found that an acceptable compromise.

What sets Valence apart is its phosphate-based lithium chemistry. Dean Bogues explained to me that with cobalt oxide chemistry, the oxygen in the oxide is releases as a fuel source, feeding the fire. The advantage of cobalt oxide based lithium ion cells is that for small format applications like PDAs, mobile phones, laptop computers, and digital cameras, the high energy density translates into longer run times.

According to Bogues, this advantage disappears once you move to larger format batteries like those used to power Segways, wheelchairs and electric vehicles.

In addition, phosphate is a relatively less expensive, readily available material, unlike cobalt, which is much rarer and consequently more expensive.

U-Charge Follows Familiar Format

With Valence's keen interest in the future potential of electric-drive vehicle batteries, they made a strategic decision to take their Saphion technology and package it in standard industry formats. As should be clear from the above photo, the Saphion batteries in Energy CS's plug-in Prius resembles your standard lead acid battery case. According to Kohler, the company's "U-Charge" large format Saphion batteries are engineered to produce an industry-standard 12 volts and be housed in conventional Group 24, 27 and U1 battery cases, typically used by lead acid starter batteries.

"We chose to keep the volume exactly the same, but develop a lithium ion alternative that could work in the same 12 volt range requirement", Kohler stated.

The result is a battery that weighs half as much as lead acid, yet twice as much energy.


<snip>

So, how does a Saphion battery compare to a comparable NiMH battery of the same volume? According to Kohler, while the energy densities will remain approximately the same, the Saphion battery will be half the weight of the NiMH. This should translate into better acceleration and slightly longer range. In terms of watt hours/kg, today's NiMH battery are rated at 50-60 wh/kg while the Saphion battery will be 90-100 wh/kg.

I asked Kohler about any possible battery "memory" issues, which long ago plagued NiCad batteries. He replied that there is no memory or depth-of-discharge issues with lithium ion-based batteries. In addition, he expects lithium-ion batteries to last 4-5 times as long as lead acid, which translates into between 8 and 15 years.

As for the cost of the batteries, he acknowledged that historically, NiMH have been cheaper, but that escalating prices for nickel on the commodity market have stalled price declines for NiMH, while lithium ion batteries have continued to drop in price.

Lithium Ion Solutions In the Works

Currently all production hybrids use NiMH batteries made in Asia, primarily by Panasonic (Toyota and Honda) and Sanyo (Ford). The proven reliability and relative cost of NiMH batteries, originally pioneered by Stan and Iris Ovshinsky at Energy Conversion Devices, had made them an attractive energy storage medium for the first generation of gasoline electric hybrids. But Kohler sees that changing.


<snip>

Significantly, Valence has also demonstrated fast charge capabilities with its batteries taking them safely from a 10 percent state of charge (SOC) to 90 percent SOC in one hour or less.

Kohler also noted that lithium ion batteries can play an important role in fuel cell vehicles where hybridization enables carmakers to reduce the size and therefore cost of the fuel cell stack, bringing affordable hydrogen-powered cars a step closer to reality.

From what I've seen, read and heard in the last few months, it's clear to me that Valence is definitely on a roll.

Reader Comments:
18/Mar/2005 Sledge _: Valence should offer the grid-chargeable Li-Ion...
19/Mar/2005 Bill Moore: Actually, that's what Energy CS is considering doi...
20/Mar/2005 Peter W: Hi Bill, The next time you talk to Valence ...
20/Mar/2005 David Navas: Re: Altair -- actually, you can read what Valence ...
21/Mar/2005 David Navas: On second read, that link appears to be charting ...
21/Mar/2005 Felix Kramer: Yes, we (CalCars and EnergyCS) hope to offer insta...

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