I know electric cars don’t need multiple gears, but wouldn’t they benefit from them in anyway at high speed for example?
In: Technology
This is because an electric motor produces the same force – the same torque – at pretty much any speed, as long as you can keep the voltage up. The torque, or force, that you get out of an electric motor is governed by the electric current you force through it, and when it comes to a motor, that is dictated only by the thickness of the wires and the design of the cooling system. But as an electric motor’s speed increases, it generates an increasing voltbe called a ‘back EMF’ impeding the current flow, meaning you need more and more voltage to push the current through.
And because a high capacity battery contains a lot of individual cells, you can reconfigure them with switches to provide really high voltages.
So really, what you have to do with gears on a petrol engine, you do by switching banks of batteries (or using an inverter to step the voltage up or down) in an electric one, increasing voltage at the expense of current and torque.
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