How Electric Cars Work

By: Marshall Brain

Electric-car Motors and Batteries

Electric cars can use AC or DC motors:

  • If the motor is a DC motor, then it may run on anything from 96 to 192 volts. Many of the DC motors used in electric cars come from the electric forklift industry.
  • If it is an AC motor, then it probably is a three-phase AC motor running at 240 volts AC with a 300 volt battery pack.

DC installations tend to be simpler and less expensive. A typical motor will be in the 20,000-watt to 30,000-watt range. A typical controller will be in the 40,000-watt to 60,000-watt range (for example, a 96-volt controller will deliver a maximum of 400 or 600 amps). DC motors have the nice feature that you can overdrive them (up to a factor of 10-to-1) for short periods of time. That is, a 20,000-watt motor will accept 100,000 watts for a short period of time and deliver 5 times its rated horsepower. This is great for short bursts of acceleration. The only limitation is heat build-up in the motor. Too much overdriving and the motor heats up to the point where it self-destructs.


AC installations allow the use of almost any industrial three-phase AC motor, and that can make finding a motor with a specific size, shape or power rating easier. AC motors and controllers often have a regen feature. During braking, the motor turns into a generator and delivers power back to the batteries.

Right now, the weak link in any electric car is the batteries. There are at least six significant problems with current lead-acid battery technology:

  • They are heavy (a typical lead-acid battery pack weighs 1,000 pounds or more).
  • They are bulky (the car we are examining here has 50 lead-acid batteries, each measuring roughly 6" x 8" by 6").
  • They have a limited capacity (a typical lead-acid battery pack might hold 12 to 15 kilowatt-hours of electricity, giving a car a range of only 50 miles or so).
  • They are slow to charge (typical recharge times for a lead-acid pack range between four to 10 hours for full charge, depending on the battery technology and the charger).
  • They have a short life (three to four years, perhaps 200 full charge/discharge cycles).
  • They are expensive (perhaps $2,000 for the battery pack shown in the sample car).

In the next section we'll look at more problems with battery technology.

AutoHybrid CarsHow Electric Cars WorkAutoHybrid CarsElectric Car PicturesAutoFuel-efficient VehiclesWill I get shocked if I drive an electric car through a big puddle?AutoFuel-efficient VehiclesHow Electric Car Batteries WorkAutoHybrid CarsWhat is a potentiometer in an electric car?AutoHybrid CarsHow Electric Car Labs WorkAutoPorschePorsche Joins Electric Vehicle Race With 2020 TaycanAutoOther Makes & ModelsCould Electric Motor Conversions Save Classic Cars?AutoUnusual CarsHow the G-Wiz Electric Car WorksAutoHybrid CarsHow Electric Car Charging Networks WorkAutoHybrid TechnologyCan I buy an electric car at Sam's Club?AutoHybrid CarsIs there a way to create an all-electric car you don't have to plug in?AutoHybrid TechnologyHow Electric Car Conversion Kits WorkAutoHybrid TechnologyWhat is the history of electric cars?AutoUnusual CarsHow big is the world's smallest electric car?AutoFuel ConsumptionHow can a speed bump harvest electricity?AutoFuel-efficient VehiclesThis Woman's Job Is to Figure Out Why People Don't Buy Electric CarsAutoHybrid CarsIs an all-electric car a bad investment?AutoTypes of EnginesHow Does an Electric Water Pump Benefit Your Engine?AutoPlug-in HybridsWhat is the plug-in electric vehicle credit?AutoFuel ConsumptionIndia Plans to Switch All New Cars to Electric by 2030AutoTech and TransportShared Electric Scooters: Commuter Solution or Urban Nightmare?AutoHybrid CarsCan Electric Car Batteries Be Recycled?AutoHybrid CarsWill Electric Cars Require More Maintenance?AutoHybrid CarsChallenges Facing the Electric Car IndustryAutoHybrid CarsAre electric cars safe in accidents?AutoHybrid CarsAre Electric Cars Cheaper to Run?AutoAuto ManufacturingHow old is the electric car?AutoConcept CarsToyota's Newest Electric Concept Car Is Made of WoodAutoFuel-efficient VehiclesElectric Car Charging Goes Super FastAutoHybrid CarsElectric Cars vs. Hydrogen Fuel Cell CarsAutoHybrid CarsTop 10 Electric Car Frequently Asked QuestionsAutoHybrid CarsHow Does Horsepower Figure Into Electric Cars?AutoFuel-efficient VehiclesTesla's New Model 3 Aims Squarely at the Electric Car MainstreamAutoFuel EconomyWill all vehicles eventually be all electric?AutoTransmissions & DrivetrainGas-powered vs. Electric Cars: Which Is Faster?AutoHybrid CarsHow Long Does it Take To Charge an Electric Car?AutoHybrid CarsHow Much Does It Cost to Charge an Electric Car?AutoHybrid Cars12 Myths About Electric VehiclesAutoConcept CarsUnveiled at CES: The Electric Car Hoping to Beat Tesla at Its GameAutoFuel EconomyGas vs. Grid: Gasoline and Electricity Face OffAutoHybrid CarsCharging an Electric CarAutoHybrid CarsInside an Electric CarAutoHybrid CarsDoing a Conversion - Electric Car ConversionAutoHybrid TechnologyThe First Electric CarAutoHybrid CarsAn Electric Car ExampleAutoHybrid CarsElectric-car Motors and BatteriesAutoConcept CarsHow the Tesla Roadster Works