Wednesday, June 17, 2009

So What Goes Into an Electric Car ?

I'm not going to go into detail on the specifications required for different vehicle builds, and the performance of different components ... (that's what Google is for)
A basic install will need the following.

The Electric Motor:

-A regular petrol engine could be ~30% efficient at turning fuel into actual energy, with energy lost as heat and noise ... whereas an electric motor can be 80-90% efficient at converting energy. -A regular petrol engine is power rated for its "peak" power at a given rpm, whereas many electric motors are rated at their continuous duty

Therefore a much smaller and lighter electric motor can be used to supply the same performance to a vehicle than its originally supplied engine.
The Controller:

An electronic device needed to adjust voltage etc ... supply to the motor. To ??? You guessed it ... "control the motor"

The Potentiometer:

Is basically an adjustable resistor which you can connect your standard throttle cable to. The potentiometer will send a signal to the controller telling it how much power to supply.


The "Achilles' Heel" of the electric cars. This is where your power (fuel) is stored. Varying battery chemistry, voltages and capacity will provide varying results for your electric vehicle. Battery technology is constantly being developed with prices dropping constantly ... I saw someone mention recently that with three factors of an electric vehicle "Cheap" Range" & "Power", you can only choose two of these. This is true due to current battery technology.

DC-DC Converter:

This is used to replace the alternator on a petrol motor ... The DC-DC converter will change the high voltage of your main battery pack to 12V to power standard car accessories like lights, windscreen wipers, radio etc. (Or can be used to charge a separate 12V battery which powers these accessories)

Vacuum Pump:

Vacuum created from a standard petrol engine is used for "power assisted brakes" ...Without the petrol engine, this vacuum need to be created to return the brakes to their original working capacity ... A 12 Volt Vacuum pump and reservoir can be sourced as a kit if required.

Power Steering Pump:

Most vehicles use a power steering pump which is belt attached to the petrol engine. But there are many vehicles which are factory built with 12 Volt electric power steering pumps like the Toyota MR2 and Holden Astra Mk4 to mention a couple. One of these power steering pumps can be easily adapted for an electric vehicle.

Battery Charger:

Usually mounted in the vehicle so you can charge from any power point.

Adapter Plate & Coupler:

Used to attach an electric motor to the vehicles existing gearbox. (usually has to be custom fabricated which means $$$)

Gauges and Meters:

Used to measure the power consumption and/or remaining battery capacity


A contactor is basically a high voltage relay or switch. It is used to turn on the main power to your controller.

Circuit Breakers or Fuses:

Used to protect the electrical circuit against surges, shorts or for safety cutoffs.

Power Cable:

Power cable for an electric vehicle needs to be much larger than any standard automotive cable.
Sizes of 2/0 or 4/0 AWG, multistrand double insulated welding cable is capable of handling the amps required for an electric vehicle. (500A plus)

1 comment:

  1. Great post John! I was looking for a automotive cable when I came across your blog post about electric vehicle conversion, I'm happy I did because this was a very insightful and interesting read. Thank you for sharing this with us.