Electric Auto Conversion: How do Electric Cars Work?

Not many people are aware that most of the on-road electric cars today are the “home-brew” conversion vehicles i.e. people, interested in electric cars convert their existing gasoline powered cars to electric ones in their garages and backyards. It can be done easily as there are many websites that tell you about the phenomenon like where to get the parts and how to do the whole process etc.

DC motor and a DC controller are used in the typical conversion. The people involved with the conversion decides the voltage that car will be run at, which can be anything between 96 to 192 volts. The number of batteries needed and what sort of controller and motor will be used by the car is controlled by voltage decision. A normal gasoline-powered car is the donor vehicle which acts as the platform for conversion and usual involves manual transmission. There are also lot of options available in case of battery technology. The person doing the conversion can choose from Golf-cart batteries, marine deep cycle lead acid batteries, sealed high performance batteries etc. And having made the decision about controller, motor and battery,
the conversion can commence with the following steps:

1. Engine, exhaust tank, radiator, clutch and gas tank should be removed from the donor vehicle. Some controllers contain air-cooled transistors while others have water-cooled.

2. An adapter plate should be attached to the transmission and motor should be mounted which usually requires custom mounting brackets.

3. As the electric motor usually needs a reduction gear for maximum efficiency, it can be easily created by pinning the existing manual transmission in second or third gear. Once this is done, controller should be mounted.

4. Find space and build brackets to safely hold the batteries and once done, install them. Sealed batteries offer an advantage here of getting turned on their sides and fitting themselves into all sorts of crannies and nooks.

5. Now wire the controller and the batteries to the motor with #00 gauge welding cable.

6. If there is power steering in the car, an electric motor should be wired and mounted for the power steering pump; and if there is air-conditioning then an electric motor for ac compressor should be wired up and mounted too.

7. Now comes few installations: Install an electric water heater and plumb it into existing heater core or you can use ceramic electric space heater, instead. Install vacuum pump to operate brake booster, in case car has power brakes. Install a charging system and a DC-to-DC converter in order to power the accessory battery. In order to detect the state of charge in the battery pack, you can install some volt-meter which replaces the gas gauge. Similarly, install potentiometer, after hooking them to accelerator pedal, connect it to the controller.

8. Most home-brew electric cars with DC motors use reverse gears built into the manual transmission. However, AC motors having advanced controllers simply run the motor in reverse order and hence just needs a simple switch to send a reverse signal to the controller. Some sort of reverse switch and wire to the controller, hence, needs to be installed depending on the conversion.

9. A large relay, also known as contactor, carrying hundreds of amps that is able to break 96 to 300 volts without carrying an arc needs to be installed to connect and disconnect battery pack to and from the controller. This relay is what turns the car “on” when we want to drive it.

10. The ignition switch now needs to be rewired to turn on all the new equipments including the contactor.
One all this is installed and then tested, the new electric car gets ready to be driven!