How exactly do  electric engines work 

surprisingly the operating principle behind most modern electric vehicles  pre-dates the internal 

combustion engine by a  number of decades in 1834 a dutch professor named  sebranda stratting of 

groningen netherlands built his own small electric vehicle the catch being its  battery was non-

rechargeable internal combustion engines work on the principle that fuel and air  when compressed and 

ignited cause a tiny explosion that's the combustion part this explosive force  pushes a piston that 

piston's linear motion in concert with a team of fellow pistons transforms  into rotary motion via a 

mechanical crankshaft this in turn spins your wheels along the highway  conversely the fundamental 

principle that drives electric cars is magnetism everybody knows how  opposing poles on a magnet 

attract and how a like poles repel each other so let's imagine an  experiment using two magnets one 

fixed the other mounted on a nearby rotating shaft if the two  poles nearest to each other on both 

magnets share the same polarity say north to north the magnet on  the shaft will be repelled because 

it's attached to a shaft the shaft will turn that is until the  south pole on the shaft magnet is aligned with 

the north pole on the fixed magnet whereupon the shaft  will again be still in our imaginary 

experiment. 

we've made the shaft turn a half rotation all  very well but that won't get us very far on the  

morning commute here's where electromagnetism  enters the chat in a fixed or permanent magnet  

like the kind you have on your fridge at home  those magnetic poles are rigid and never change  

north is always north south is always south on  an electromagnet however which is essentially  

a core of metal coiled in electrical wires this  magnetic polarity can be reversed imagine one of  

our experimental magnets is now an electromagnet  if the south pole quickly flips over to north  

the fixed magnet will yet again repel the moving  magnet rotating our shaft another half spin that's  

a whole spin now we're slowly getting there for a  basic illustration of how this polarity reversal  

works imagine a very simple circuit involving  a battery and a light bulb electrons flow in  

one direction from the battery through the wires  to the light bulb and back again to the battery  

if we remove our battery from the circuit flip  it 180 degrees then replace it in the circuit  

those electrons will still flow around the  circuit just in the opposite direction either  

way the bulb lights up electromagnets like light  bulbs work whichever direction the electrons are  

flowing but rather brilliantly the polarity of the  magnet gets reversed with the flow of electrons so  

to keep our magnets in permanent repel mode we  just need to keep reversing the polarity of the  

magnet how do we do that one way would be to keep  popping out the battery and flipping it around  

but that's a lot of trips to the mechanics with  your ev for the sake of a few feet of ground  

covered so the real trick to making a magnet spin  which is essentially how electric motors work  

is through the so-called inverter the inverter  module on the ev draws direct current from the  

car battery and through a clever combination of  quick switches slick circuitry and capacitors  

flips the flow of electrons back and forth nearly  60 times a second domestic electric motors like  

the one you have in your hairdryer don't require  an inverter why because the current that comes  

from your wall outlet already flips back and  forth that's why it's named alternating current or  

ac batteries of any type can only ever produce  dc or direct current so spinning magnets driven  

by alternating current passing through coils of  wire is essentially what drives electric cars  

electric powertrains have a number of advantages  over the internal combustion engine for starters  

the motion produced by the motor is already  rotary in nature dirty pistons on an ice require  

a complicated breakable crankshaft just in order  to turn their linear motion into rotary movement  

so evs are less likely to fail or require  expensive time-consuming maintenance here's  

another clever thing about that inverter by  adjusting the frequency and amplitude of its newly  

created ac current the vehicle's speed and torque  can be finally calibrated by its driver there's  

no such fine control built into an explosively hot  internal combustion engine which is why expensive  

and accident-prone additions like gearboxes are a  tiresome necessity another nifty detail about any  

ev's powertrain is when the shaft-mounted magnet  or rotor in engineering parlance is itself spun  

it generates electricity this reversal very  handily recharges the car battery how can  

the rotor be turned you ask with any hefty source  of kinetic energy like say a breaking automobile  

which is handy this is to be clear a very simple  overview there's different types of electric motor  

and refinements to the design are happening all  the time not least at one particular californian  

car company named for the 19th century genius  who discovered the magic of alternating current  

by himself.