You have decided to build an electric car. There are a wide variety of electric car components available. Understanding these components and their specific purposes is the first part of building your own. Below is a list of the most common parts that the home electric car builder will need to build a car that meets the needs of the average driver.
Every electric car needs a motor. Electric motors vary in shape and size, weight and price. They can use AC or DC electricity. A budget builder may choose to use an electric motor from an old forklift or elevator system. There are also lots of electric car-specific motors available for purchase alone or as part of a kit. You will need to choose a motor that will suit your needs for performance and budget.
The purpose of the motor controller is to adjust the speed at which the motor spins. If 120V were applied directly to an electric motor for example, it would run at full speed. There needs to be a means of adjusting the output of the motor and this is precisely what the motor controller is for. It allows the motor to run at any speed between zero rpm and its max rpm. This part can also be salvaged either from a forklift or golf cart.
Throttle Pot Box
A pot box is a small part that connects to your stock throttle cable. When you push on your throttle, the pot box sends a signal corresponding to the amount of pressure you’re putting on the pedal to the controller which then sends the proper power to the motor.
The adapter plate mates the electric motor to a stock transmission. These can be bought for any commonly converted vehicle. Most EV-specific motors have a standard bolt pattern so most adapter plates will work with most motors. If you use a motor from a forklift you will need to have an adapter plate custom built or of course if you’re a decent fabricator you can always do this yourself.
This is basically a high-voltage relay. It connects your battery pack to the controller when you turn on the key.
A fuse will blow and cut power when too much amperage is drawn.
There needs to be one (or more) manual disconnects for the main battery pack. This way if all else fails you can manually disconnect the power and safely stop the vehicle.
There are many different types of batteries available. The type of batteries that you choose will affect your performance and range.
There are many different types of chargers available and the charger you need will depend on the batteries you use.
The DC/DC converter takes the voltage of your main (traction) battery pack and reduces it to 12V which keeps your 12V battery charged. An electric vehicle still needs an 12V battery to power all the lights, stereo, horn etc. Keeping this battery charged can be achieved other ways as well. Some EV builders use an alternator that runs off the electric motor and others use a separate 12V charger to charge this battery.
You will need to know what’s going on under the hood and this is where your gauges come in. Most basic EV builds use a high-voltage ammeter and voltage gauge (for traction pack voltage) and a low voltage gauge (12V system).