They are too slow, I don't want a golf cart

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A golf cart is slow because it doesn't need to be any faster. A typical one has 8 batteries, each providing 6 volts, for a total of 48 volts (since they are wired in series). For a freeway-going car, of course you need more than that. Something between 96 and 144 volts is reasonable, if you plan to use lead-acid batteries and a DC motor. If you want to invest in an AC motor and a 3-phase inverter with which to drive it, then you need several hundred volts, and typically you will be using a larger quantity of smaller batteries in that case (and will be spending quite a bit more money too).

Unfortunately there is a legal classification for slow electric cars, called the "Neighborhood Electric Vehicle" (NEV), and since these cars are not required to meet a lot of stringent qualifications, pass a crash test, and so on, the manufacturers are not afraid to produce and sell them. These are just golf carts with a few extras, and are not what we are talking about here.

Some well-known quick DC conversions

These are ordinary back-yard conversions of everyday cars, built by everyday people like you.

  • White Zombie is a Datsun 1200 conversion that happens to run 12-second 1/4 mile races
  • California Poppy is a car built by the engineer who has designed the best high-power DC motor controller so far
  • Gone Postal used to be a mail delivery van, and has been turned into an electric race car, just to turn heads at the track
  • For more electric racing excitement, check out the National Electric Drag Racing Association.

Some more exotic electric racers

  • T-Zero was designed as a test bed for AC inverter development, and runs from a pack of hundreds of laptop batteries. (They happen to have the best energy density, but wiring up that many into a single pack is a bit of work!)
  • Current Eliminator is currently the fastest electric dragster; runs 1/4 mile races in less than 9 seconds.
  • The Buckeye Bullet holds the electric land speed record, at 314.958 mph.

An internal combustion engine must operate within a certain RPM range. It must already be running, it cannot provide instant torque at the same time that it is being started. And it has a redline, of course. And the rated horsepower that the engine can deliver, is measured as a maximum, and can be achieved at only one speed, the speed at which the engine is the most efficient.

But an electric motor can provide instant torque, from a standstill. A series-wound DC motor, in particular, actually provides the *most* torque in preciesly that condition. So, a transmission is not necessary in many of these race cars. A series-wound DC motor is ideal for drag racing. The problem is not getting enough torque, but keeping the tires stuck to the track rather than spinning out of control. If you can do that, you're nearly guaranteed to get a quicker launch than any gas-powered vehicle can muster.

The racers are constantly pushing out the limits of power, and figuring out how to control more power; but for a street car, the design goals are a bit different. You typically want to drive as far as possible without needing to recharge the batteries too often. But that's mostly a matter of carrying more batteries.