How It Works

When you build a car thats electric, you start with one built-in advantage: Electric cars just dont have to be as complex mechanically as the car youre probably driving now. Sophisticated electronics and software take the place of the pounds and pounds of machinery required to introduce a spark and ignite the fuel that powers an internal combustion engine.

For example, the typical four-cylinder engine of a conventional car comprises over a hundred moving parts. By comparison, the motor of the Tesla Roadster has just one: the rotor. So theres less weight to drive around and fewer parts that could break or wear down over time.

But the comparison doesnt end with the counting of moving parts. The engine and transmission of a conventional car also need lubricating oils, filters, coolant, clutches, spark plugs and wires, a PCV valve, oxygen sensors, a timing belt, a fan belt, a water pump and hoses, a catalytic converter, and a muffler  all items requiring service, and all items that arent needed in an electric car.

The Tesla Roadsters elegantly designed powertrain consists of just the four main components discussed below. Mind you, these arent "off-the-shelf" components, and each includes innovations, both small and large. But when you build a car from the ground up, you have the luxury of questioning every assumption  and to distill as you reinvent.

The Energy Storage System (ESS)

When we set out to build a high-performance electric car, the biggest challenge was obvious from the start: the battery. Its complexities are clear: its heavy, expensive, and offers limited power and range. Yet it has one quality that eclipses these disadvantages and motivated us to keep working tirelessly: its clean.

The Tesla Roadsters battery pack  the cars "fuel tank"  represents the biggest innovation in the Tesla Roadster and is one of the largest and most advanced battery packs in the world. Weve combined basic proven lithium ion battery technology with our own unique battery pack design to provide multiple layers of safety. It.s light, durable, recyclable, and it is capable of delivering enough power to accelerate the Tesla Roadster from zero to 60 mph in approximately four seconds. Meanwhile, the battery stores enough energy for the vehicle to travel 250 miles without recharging, something no other production electric vehicle in history can claim.

Motor

Some people find it hard to imagine our cars Lamborghini-beating acceleration comes from a motor about the size of a watermelon. And while most car engines have to be moved with winches or forklifts, ours weighs about 70 pounds  a strong person could carry it around in a backpack (although we dont recommend it). Compare that to the mass of machinery under the hood of $300,000 supercars that still cant accelerate as quickly as the Tesla Roadster.

But more important than the motors size or weight is its efficency. Without proper efficiency, a motor will convert electrical energy into heat instead of rotational energy. So we designed our motor to have efficiencies of 85 to 95 percent; this way the precious stored energy of the battery pack ends up propelling you down the road instead of just heating up the trunk.

Transmission

Our transmission couples the fuel efficiency of a manual with the driving ease of an automatic. The Tesla Roadster has only two forward gears, allowing you to fine-tune your driving experience (but either gear will work for most driving scenarios). Unlike a manual transmission, the car will not stall if you have it in the wrong gear. Theres also no clutch, so you can launch from a full stop to freeway speed without taking your focus off the road, your foot off the accelerator, or your hands off the wheel.

Power Electronics Module (PEM)

Most of the subsystems in the Tesla Roadster are completely electronic and under direct software control. But unlike all other cars, these systems are not a hodge-podge of independent systems  instead, they are designed as an integrated system, the way complex network and computer systems are designed today.

Youll see the hub of this network every time you pop the trunk  the Power Electronics Module. When you shift gears or accelerate in the Tesla Roadster, the PEM translates your commands into precisely timed voltages, telling the motor to respond with the proper speed and direction of rotation. The PEM also controls motor torque, charging, and regenerative braking, and it monitors things like the voltage delivered by the ESS, the speed of rotation of the motor, and the temperatures of the motor and power electronics.

The PEM controls over 200 kW of electrical power during peak acceleration  enough power to illuminate 2,000 incandescent light bulbs.

Formated for CROWN by Nenad Bach
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