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(reprinted from the April/May 2002 issue #88 of Home Power magazine.
Frank was bored and restless. Mary knew she had to find a project for him, something big enough to hold his interest and absorb his seemingly endless energy for a while. It was a situation any mother of an adolescent would recognize. Only Mary Mendes wasn't Frank's mother, she was his niece. And Frank Silveria was a long way past adolescence. He was 94 years old.
"Why don't you build me an electric car?" Mary challenged him.
"I don't know anything about cars," Frank said.
"No, but you know about electric motors. Build one for me." Mary replied.
So he did.
Frank's preparation to be an electric car builder began when he was a small child growing up in the California central valley town of Gustine. When his mother was only twenty-five years old, she lost both her husband and youngest child. This left her as a young widow who spoke little English, with four small children to raise and a farm to run.
Frank was the second oldest, and became the farm handyman. He soon had a reputation for being able to fix any piece of equipment, as well as build original devices. Once, he built his own system for pumping water from the well by using a Model T Ford for power.
At the age of fourteen, his career path was decided by the young girl who would one day be his wife. "I won't marry any farmer," she told him firmly. So Frank started to look around for some other line of work. He started fixing radios. From this, he moved into repairing electric motors, and finally become a fully qualified electrical contractor. By the age of 25, Frank had his own business. When the town of Gustine got its first electric streetlights, it was Frank Silveria who installed them.
Later, the dam at the nearby San Luis Reservoir started to have problems. The huge motors used to pump water into the reservoir during off-peak times kept breaking down. Frank, the local electric motor genius, was called in to fix them. He diagnosed a failure caused by vibrations from the impellers. He repaired and modified the motors, one by one, to make them more durable, and the failures ended.
In the 1950s, Frank moved to the larger town of Los Banos and continued his electrical work. His favorite niece, Mary, worked in the shop under his supervision for many years also. In 1989, at age 83, Frank sold his shop.
With too much energy to "retire," he set up a shop at home, where a large barn and other outbuildings sat filled with a lifetime's accumulation of tools, machinery, parts, and discarded machines waiting to donate usable pieces. He became the person neighbors would call with farm equipment emergencies, or bring motor problems that no one else could fix.
When Mary needed a place to live that was closer to her work, Frank invited her to move into his house, since he had plenty of room. The stage was set for his adventure into electric car building.
The Main Pieces
Frank and Mary researched electric conversion kits and donor cars. They found a 1987 diesel VW Jetta as the donor car, and chose a conversion kit from Electro Automotive (which was a two-hour drive away in Santa Cruz, California). They chose the car because of the great condition of the body and interior. Mary wanted something attractive that she would be proud to drive. The engine was still in good running condition when they bought it. At US$1,500, they felt that it was an excellent deal.
Frank's mission now was to fit all the pieces together, physically and electrically, in a safe package. With the assistance of Jeff Brubaker, who helped with the heavy lifting, and a couple of consultation visits to Mike Brown at Electro Automotive, that's just what he did. Here are the pieces he used, and where he put them.
The drive system components are popular off-the-shelf parts for electric car conversions. The motor is a 19 KW brushed series DC motor from Advanced D.C. Motors in East Syracuse, New York. It is rated for 25.2 hp continuous duty and 85 hp peak on the 120 volt system Frank planned to use. This doesn't sound like much power to people accustomed to hearing about gas cars, but the numbers are deceptive. Electric motors get their highest torque when starting from a standstill, and this system provides plenty of power for the Jetta.
The motor is mounted to the original manual transmission by an aluminum and steel adaptor system. The adaptor mounts the electric motor to the transmission and clutch in the exact position the engine previously occupied, by means of a pair of precision-machined aluminum plates. The motor shaft is connected to the flywheel by a tapered split steel bushing inside a matching tapered steel hub. Once tightened into place, this grips the motor shaft with an even, secure pressure all around.
The speed controller is a pulse width modulated unit from Curtis/PMC of Dublin, California. The controller is, in basic terms, a very sophisticated switch. It turns the full battery pack potential of 120 volts on and off 15,000 times per second, feeding this to the motor.
"Pulse width modulated" means that the number of pulses per second remains constant. Speed is controlled by varying the duration, or width, of each "on" pulse. The end result is that the motor's momentum carries it through the tiny "off" pulses smoothly, so it feels like continuous power. Frank mounted the controller behind the front grill where the radiator used to live. This is a good place for it to get the cooling airflow it needs.
The speed controller determines how much to "chop" the pulse based on the signal from a 0 to 5 k-ohm potentiometer connected to the throttle pedal. The electricity to power the motor comes to the controller from a pack of fifteen golf cart batteries, wired in series for a total pack voltage of 120 volts.
Frank decided to go with the 8 volt batteries from U.S. Battery in Corona, California, rather than the more commonly used 6 volt batteries. This was a tradeoff between range and performance. Mary's range needs were modest. Using the 8 volt batteries meant a slightly lighter pack (with slightly less range), but a higher pack voltage, for a higher top speed.
These are flooded lead-acid batteries, so they will need to be watered from time to time-probably more often in the hot summers of Los Banos than they would in milder climates. They are "traction" batteries, designed to move a vehicle. Unlike regular car starting batteries, they can take repeated deep discharges for hundreds of cycles. Unlike marine or RV batteries, they can also take the high current draws of an electric vehicle.
Frank packaged the batteries in polypropylene boxes. This makes an attractive acid-proof container that isolates the batteries, their connections, and any acid or fumes from the chassis and passengers. He bought the plastic sheet in Sacramento, and built the boxes himself. He didn't weld them, since that requires special equipment. Instead, he bolted them together.
The boxes were then clamped into steel racks, with one part supporting and securing the boxes from below, and a second part framing the top of the boxes. All of this was firmly bolted to the chassis to keep the batteries securely in place, even in a collision. The steel racks are powdercoated to give them extra protection from rust and corrosion.
There are five batteries in front, under the hood. Ten more batteries are in the trunk. Most of the rear batteries are recessed into the floor of the trunk to keep the weight low for stability. The back seat is still fully usable for passengers.
The other main component of the drive system is the charger. This is an onboard unit from Russco, of Santa Rosa, California. The charger plugs into a normal household 120 volt grounded receptacle on a 15 amp circuit. If the battery pack is completely discharged, it will fully recharge it overnight, gradually tapering to a low current "finish" charge as the batteries come up to full.
There are other small but necessary parts to the conversion as well. These include dash gauges for information on electricity use, a circuit breaker, an on/off main contactor, and fusible links for safety power disconnects. An ordinary 12 volt battery powers the horn, lights, and other accessories. It is kept charged by a DC-to-DC converter that taps the main battery pack at high voltage and low current and converts this into a low voltage, higher current output appropriate for the accessory battery.
The car had factory power brakes as well. This is a good thing, since it gained several hundred pounds in the course of the conversion. Since there is no longer any engine manifold vacuum to power this system, a substitute arrangement had to be made. This involves a small electric vacuum pump powered by the accessory battery, a vacuum switch, an ABS plastic vacuum reservoir, and some brass fittings and hoses. Of these items, the gauges and circuit breaker are the only ones in the passenger compartment. The rest are all installed under the hood.
The Jetta also came with power steering. This could have been maintained in the conversion, but not as easily or affordably as the power brakes. Considering the size of the car, power steering wasn't really necessary, so Frank simply removed it and replaced it with a manual steering rack.
The final area of concern was the suspension. Frank left this until last, to see just how much adjustment it would need in its new configuration. When the car was completed, it drove well with the existing suspension, albeit somewhat lower than the original. Frank still plans to beef this up, but it doesn't seem to be an urgent issue.
Oh, and one more thing-the paint job. Mary wanted to be sure that the car got noticed, so she had it painted hot pink. For good measure, she added lettering on the doors that reads, "Electric Car by Frank Silveria." The former gas cap, which now covers the charging cord, sports an icon of an electrical outlet.
At last, after six months, it was done. The car was finished just in time to make its debut in the town's Christmas Day parade. Taking advantage of all the available electricity, Frank and Mary trimmed the car with Christmas lights to get into the spirit of things.
Mary is delighted with her car. It drives just like any other car in traffic, and handles very well, even without any suspension modifications yet. The lack of power steering is not noticeable. Mary's round trip into town is 8 to 10 miles (13-16 km), and she has made as many as three trips in the same day. Range will improve as the batteries continue to break in.
Mary is also learning some new electric car driving skills. At the beginning, she found that she could start in first, and shift directly into third. This felt fine, but she learned that it was not very efficient and shortened her range. For the low speed driving she does most of the time, second gear is more appropriate and will give her better mileage. She has also discovered that she can release the throttle long in advance of a stop and coast for quite a distance, slowing down much more gradually than in a gas car. This technique adds to efficiency, too.
Performance is better than Mary expected. (She doesn't always drive slowly!) She has had the car up to 65 mph (105 kph), and brags that she can peel out from a stop quite impressively too.
Mary also loves the attention the car gets. The hot pink catches people's eyes first. Then they read the lettering. If she's in motion, Mary sees the smiles, wide eyes, pointing fingers, and waves. If she's parked, she knows she'll soon attract a crowd full of questions.
While the car was being built, Mary's gas car began to show its age, so she decided to buy a new Toyota Solara sport coupe. She likes it a lot, but since the Jetta hit the road, the Toyota spends much of its time in the garage. Mary's sister asked her why she has that nice new car and never drives it. Mary replied, "Because driving the electric car is so much more fun!"
Boys Will Be Boys
Soon after the car was finished, Frank celebrated his 95th birthday, and will soon be fidgeting for a new project. If you ask him about the electric car, he'll be happy to open the hood and give you the grand tour, explaining every piece and what he did to put it where it is. And when you look at his face, you'll see the big grin of one very satisfied kid.
Shari Prange, Electro Automotive, PO Box 1113-HP, Felton, CA 95018 * 831-429-1989 * [email protected] * www.electroauto.com
Frank Silveria & Mary Mendes, 21480 W. Sunset Ave., Los Banos, CA 93635 * 209-826-4382
U.S. Battery Manufacturing Co., 1675 Sampson Ave., Corona, CA 92879 * 800-695-0945 or 909-371-8090 * Fax: 909-371-4671 * [email protected] * www.usbattery.com * Batteries
Russco Electro-Mechanical Engineering, PO Box 3761, Santa Rosa, CA 95402 * Phone/Fax: 707-542-4151 * Charger
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