How does an electric car's motor turn a battery into motion?

An electric car's motor turns a battery into motion by using a magnet and a current in a wire to make a twisting force. An electric motor converts electrical energy into mechanical energy. Most work through the interaction between a magnetic field and the current in a wire winding, which produces a Lorentz force in the form of torque on the motor's shaft. A motor has two mechanical parts: the rotor, which moves, and the stator, which does not.

In an electric car the battery supplies direct current. Usually that electricity is fed into an inverter that converts it into alternating current, which goes to a three-phase AC motor. Most electric cars use lithium-ion batteries, which have higher energy density, longer life and higher power density than most other practical batteries.

The surprising part is what the motor does not need. Unlike a combustion engine, an electric motor gives high torque from stationary to moving, and it does not need multiple gears to match its power curve, which removes the need for gearboxes and torque converters. It can deliver its maximum torque over a wide range of rpm.

The idea is old. On 3 September 1821, Michael Faraday gave the first demonstration of rotary motion from electromagnetism: a free-hanging wire dipped into a pool of mercury, with a permanent magnet placed in it. Electric vehicles themselves originated in the late 19th century, when electricity was among the preferred ways to power early cars because it was quieter and easy to operate.