The Tesla Roadster, a two-seat electric vehicle being commercialized by Tesla Motors has become the poster child for electric cars. The company claims the vehicle will go from zero to 60 miles per hour in about 4 seconds and travel 250 miles per charge, at an operating cost of about 1 cent per mile.

The combination of a lithium-ion battery pack, a 248-horsepower electric motor, an aluminum chassis, and a beautiful design has gained the company plenty of media attention and led people to reserve the first 100 cars. Their initial run of 100 cars sold out in less than three weeks. Demand was so strong, Tesla Motors found itself bumping people, on the waiting list, who ordered a car but couldn't pony up the $100,000 deposit fast enough, said Mike Harrigan, Tesla's vice president of marketing. The British automaker Lotus provides the chassis and suspension from its Elise to make the Tesla. Lotus designers also created the exterior of the Tesla. And the car will be assembled at the Lotus factory in Norwich, England.

The Tesla Roadster has only two forward gears and either one will work for most driving. Unlike a manual transmission, the car will not stall if it's in the wrong gear. Plus it puts you in control of the shifting to fine-tune your driving experience or to achieve the upper limits of acceleration and top speed. And because there is no clutch, you can quickly and easily start from a stop or shift gears on the freeway.

The Tesla has a carbon-fiber body, but it is heavier than similarly performing sport cars - 1,000lbs of its total weight of 2,500lbs comes from its battery, made up of 6,831 liquid-cooled, lithium ion cells of the kind used to power laptops. Tesla promises that the battery can be recharged in around three hours, gives a range of 250 miles and has a life of at least 100,000 miles, after which it can be recycled.

Plug it in at night when you pull into the garage, and you can drive about 250 miles on that charge the next day.

Just like the fuel gauge in your existing car, the instruments inside the Tesla Roadster indicate how many more miles can be driven before you need to think about recharging. So unlike the old days of electric vehicles, now you can “drive electric” without the anxiety you’ll run out of charge and be left stranded.

The battery system weighs in at about 1,000 pounds and delivers four to five times the energy-density of lead acid batteries. Safe, light, durable, and recyclable, it is one of the largest and most advanced lithium-ion battery packs in the world. The system uses commodity lithium ion cells which, thanks to high demand by the consumer electronics industry.

The system addresses thermal balancing with a liquid cooling circuit. Multiple passive and active safety devices ensure safe operation over the wide range of driving environments and scenarios. An array of sensors and a dozen microcontrollers communicate with the vehicle to allow efficient use and management of the battery pack. The entire assembly is housed in a rugged enclosure, which protects the system from the harsh road environment while supporting the internal components.

Telsa collaborated with an outside firm known for expertise in lithium ion battery safety to perform hundreds of tests to validate the safety of the design. In these tests, they set out to simulate a worst-case scenario in which a cell develops a serious malfunction. In each test, they set a cell on fire in the middle of a battery pack (by heating the heck out of it) and observed the results. The design contained these failures to a single cell, demonstrating that malfunctions wouldn’t spread.

TECHNICAL DATA

Motor	Type designation 3-phase, 4-pole electric motor Max net power 185kW Max rpm 13,500 Efficiency 90% average, 80% at peak power
Transmission	Type: 2 speed electrically actuated manual transmission with final drive; constant mesh gears and inertia lock key type synchromesh Gear Ratio Overall First 4.20 : 1 14.3 : 1 Second 2.17 : 1 7.4 : 1 Final Drive 3.41 : 1   Reverse reverse direction of motor
Front Suspension	Type: independent; upper and lower wishbone; co-axial coil spring/telescopic damper unit; anti-roll bar
Rear Suspension	Type: independent; upper and lower wishbone; co-axial coil spring/telescopic damper
Brakes	Type Cross-drilled 300 mm front and 310 mm rear discs with curved vane ventilation; AP Racing Two piston Aluminum fixed front calipers; Brembo Single piston sliding rear calipers Operation    Vacuum pump driven Servo assisted with 4 wheel ABS system
Wheels	Type Forged Light alloy Size - front 5.5J x 16 Size - rear 7.5J x 17
Tires	Type Yokohama Neova AD07 LTS Size - front 175/55 R16 Size - rear 225/45 R17

Weight                           Around 2500 pounds (subject to complete safety and durability testing)  

The car is, for now, only being sold in the US, and even there, only in the few major cities that will host Tesla's service infrastructure. While the electric car requires very little maintenance - certainly nothing like the multibillion-dollar industry fostered by the major car manufacturers - it will require a periodic check. Tesla wants its own engineers to do this, and plans to collect customers' cars on a flat-bed truck, take them to a workshop, rotate the tires and check the electrical system.

Tesla hopes to sell 500 to 600 cars next year and perhaps 2,000 to 2,500 a year starting in 2008. Tesla is also developing a four-door, all-electric sedan which, according to Martin Eberhard, Tesla's CEO, will be "big, fast and efficient - don't think Corolla, think BMW." The company is planning on selling the sedan, to be built in the United States, with a price of less than $50,000, by 2008.

Have $100,000 and miss out on the initial rush to buy a Tesla? The company is taking orders for the next 100 cars. Visit http://www.Teslamotors.com.

Resources:

Batteries Included, The Guardian, Tuesday August 22, 2006