AC Propulsion VW Golf EV conversion
VW conversion with 180 HP electric motor and a $1400 lead acid battery pack that gives the car a 60-70 mile range similar to current state-of-the art fuel cell vehicles costing 1000 times more.

Fuel Cell Disruptor - Part 2

Conclusion of testimony before California Air Resources Board, December 5, 2002.

By Alec Brooks

There has been some disappointment expressed by members of the board that battery technology for electric vehicles hasn’t progressed nearly as much as had been hoped.

The reality is that battery technology has progressed significantly in the last decade. But vehicle manufacturers haven’t been applying that technology in new products. It is interesting to look at what kinds of battery electric vehicles we could have had by now and to compare them with fuel cell vehicles. The results may surprise you.

I will comment on three types of batteries: Lead Acid, Sodium Nickel Chloride, and Lithium Ion. There are of course other types of batteries such as nickel metal hydride that work well in EVs and that bear a renewed look.

Our firm did a conversion of a 4 passenger lead-acid powered Volkswagen Golf. It is fun to drive with about 180 horsepower and it works very well for commuting. The total cost for the battery modules in this car is only $1400. This is based on a quote from the battery manufacturer. The range is adequate – about 60 to 70 miles.

As an aside, CARB should stay away from any ZEV regulatory structure that dictates or rewards range. That could be construed as regulating efficiency. The risk I see in the proposed regulatory structure is definition of vehicle types by range capability.

It might be reasonably argued that the most cost effective way to meet some range target is to improve vehicle efficiency rather than put in a larger or more expensive battery pack. That could be an opening for future attacks on the mandate from Automakers on the basis of preemption of the Federal fuel economy laws.

The sodium nickel chloride battery, also known as the ZEBRA battery, is an advanced technology that is now coming to market. With 120 Wh/kg, the specific energy is four times that of lead acid. The price in low volume is $500 per kwh. For high volume, the price will be $220 per kWh. Life is at least 1000 cycles and calendar life is long too.

We are looking into retrofitting a GM S10 EV with two ZEBRA packs and an AC Propulsion drivetrain. Empty weight will be reduced several hundred pounds and the range should be 200 miles.

ZEBRA Battery
  • In production in Switzerland
  • 120 Wh/kg for pack (4x lead acid)
  • 1000 cylces at nameplate rating
  • No calendar life issues
  • Pricing
    Low vol. $500/kWh
    High vol. $200/kWh
    (24kWh pack: $5280)

To demonstrate the type of EV that could be made with the ZEBRA battery, we have developed a concept based on the Prius. The Prius includes most of what you need to make a basic EV – electric drivetrain, electric power steering, electric power brakes, 4 door lightweight body, low rolling resistance tires, all for a retail price of $20,000. A 24-kWh ZEBRA battery pack will just fit under the rear seat. Range should be 140 miles.

Using the existing Prius drive motor, it would be a low power EV suited for urban travel, but would be freeway capable. (A minor modification to the Prius transmission would eliminate the 41mph limit on electric power alone.) The battery should last at least 10 years and 100,000 miles.

Prius EV Concept Vehicle
Parts added:
  • 25 kWh ZEBRA battery pack
  • Charger and inlet
Parts removed:
  • Hybrid battery pack
  • Engine
  • Radiator
  • Ring gear
  • Fuel tank
  • Engine control unit
  • Exhaust aftertreatment system
Range: 140 miles
Weight: same as standard Prius
Cost to make: same as standard Prius (+/- 10%)

The cost picture looks pretty good for this vehicle. In low volume as a conversion of the standard Prius, the main parts costs would be the Prius – $20,000, the battery pack – $12,000, and the charger -- $1500, or a total of $33,500. But there would be quite a few leftover parts which might have some residual value: These include the NiMh hybrid battery pack, the IC engine, the fuel injection system and engine control computer, the exhaust aftertreatment system, the fuel tank and evaporative emissions hardware, and the radiator.

The costs look even better if this vehicle were produced in higher volume by Toyota as a ZEV in the first place. Then all costs for all those extra parts would not need to be incurred in the first place, and the battery cost would be down to $5300 (This is from the manufacturer of the ZEBRA battery). The manufactured cost would be very close to that of the standard hybrid Prius, possibly lower. The vehicle weight would be about the same as the standard Prius too.

Lithium Ion batteries hold much promise for vehicle application. The best lithium ion batteries pack 40 percent more energy per kilogram than the ZEBRA battery, and five times as much as lead acid. All of the action in lithium ion batteries has been for consumer applications – laptops, cell phones, and hand held computers. There is intense competition in this market; performance keeps going up and prices keep coming down.

We recently purchased a few kWh worth of small Lithium Ion cells. The price was $490/kWh. By contrast, our price from Panasonic for lead acid batteries has been $500 per kWh. In very high volume these lithium batteries sell for only $257/kWh. We are exploring the possibility and practicality of using these 2-Amp–hour cells in an EV. A large number of cells would be required but the costs might be acceptable.

We’ve looked at putting a pack of these lithium ion cells into the Prius EV described above. The energy on board would be about 34 kWh and the vehicle weight would be on about the same as the stock Prius. Range would be between 160 and 200 miles.

Below is a comparison of this vehicle to the Ford Focus FCV. They are both compact four door sedans and have essentially the same driving range. But the Prius weighs 700 pounds less than the Focus FCV. The Prius EV power system takes up less volume than the Focus’s fuel cell power system, resulting in more interior room and a much bigger trunk. If the Focus was refueled with hydrogen produced with electricity, it would take 240 kWh to produce the 4kg of hydrogen it needs to refuel. The Lithium Prius EV would need only 38 kWh – for the same driving range.

Focus FCV Prius Lith-Ion Concept EV
Range 200 miles 160-200 miles
Energy Storage 4 Kg Hydrogen 34 kWh Lith-Ion
Curb Weight 3528 lbs. 2800 lbs.
Electrical Energy To Refuel 240 kWh 40 kWh

If the Prius EV were loaded down with more lithium batteries to equal the weight of the Focus FCV, it would have 400 miles range.

Another good example is a comparison of the Honda EV plus and Honda FCX, which is based on the EV plus. The EVplus weighed in at 3590 pounds, including 950 pounds of nickel metal hydride batteries. The FCX comes in higher at 3837 pounds. The FCX EPA range is 170 miles, about twice that of the EVplus. But consider what would happen if the EVplus were fitted out with a sufficient amount 2003-technology lithium ion batteries to bring its weight up to that of the FCX. That lithium ion pack would deliver 75 percent more electrical energy than is produced by the fuel cell system in the FCX!

How about a battery electric Toyota Highlander? Even with many special lightweight body components, the FCHV weighs in at 4100 pounds, 616 pounds more than a 4 cylinder Highlander. An all electric 4100-lb Highlander employing lithium Ion batteries would have range of more than 300 miles.

Finally, here is the GM Hy-wire – the most expensive concept car GM has ever built at $10 million. This 4 door weighs in at 4180 pounds – about as much as a 7 passenger minivan. Those three hydrogen tanks in the 11-inch-thick skateboard chassis hold 2 kg of hydrogen. The range is only 60 miles. With higher pressure 10,000 psi tanks, the range would increase to only 100 miles.

Weight 4180 lbs.
Hydrogen storage 2 kg @ 5000 psi
3.36 kg@ 10,000 psi
Range 60 miles (5000 psi)
100 miles (10,000 psi)

Below is a 4 door EV we built at AC propulsion. It has a range of 90 miles and weighs 3110 pounds – more than 1000 pounds less than the Hy-wire. If it had a big lithium ion pack that brought the vehicle weight up to 3700 pounds, still 480 pounds less than Hy-wire, it would have a range of 400 miles.

In summary, these are the major points to keep in mind:

With these challenges with fuel cell vehicles, why are automakers putting so much emphasis on them and hoping that battery electric vehicles will go away? I have a couple of thoughts on why this might be so. First is that decision makers in the auto companies and the government may have never been through the numbers in the way I have shown.

Second, is that automakers seem more comfortable with R and D and demonstration programs, but really don’t like putting advanced technology vehicles out on the market. Working on fuel cell vehicles gives automakers an excuse to ask for relief on battery electric vehicles – which can be brought to market now at very little cost penalty. But when Toyota – the company that sells the Prius for $20,000 and makes a profit – says that only after a great deal of effort will fuel cell vehicles come down to 2 to 3 times the cost of conventional vehicles, you can see the writing on the wall that we’ll be back here again in ten years hearing all about why fuel cell vehicles can’t be produced for general use.

With the new proposed regulations, I fear that CARB is now poised to snatch defeat from the jaws of victory. Really good battery electric ZEVs are now possible; now is not the time to give up on them. Do not bet the farm that fuel cell vehicles are just around the corner. The ZEV mandate should not single out fuel cell vehicles for extra large credits and should not provide credit for fuel cell infrastructure. Fuel cell and battery ZEVs should be on equal footing. Let fuel cell vehicles sink or swim based on their merits, and please don’t structure the revised mandate in a way that would in essence abandon the only kind of true ZEVs that have already made it to end users.

Times Article Viewed: 20249
Published: 15-Dec-2002


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