This article will give you a rudimentary idea about building an electric car by converting a gasoline powered one. The conversion and building of the car is by no means a simple job and requires meticulous study, detailed planning and execution. The essential idea to be grasped here is that while building an electric car, you are replacing the gasoline power source of a car with an electric source. The gasoline engine will be replaced by a controller driven electric motor and powered by rechargeable batteries.
How Does an Electric Car Work?
Through external observation, it's tough to distinguish an electric car, from a normal gasoline powered car. The only way you can discover the difference, is by driving one or by opening the front hood of one such car and peeking inside. They are almost noise free compared to other cars.
If you know the insides of normal cars, they are like huge plumbing projects. Whereas, an electric car is a huge wiring project. The heart of these cars is the AC motor, powered by an electric battery and the brain is a DC controller, that controls the power output.
In an electric car, when you step on the accelerator, potentiometers attached to them deliver proportional electric signals to the controller. The controller delivers power to the AC motor mechanism, that drives the car forward. It's an electronic device that converts DC power delivered by batteries, into an AC voltage output, which drives the AC motor. The controller achieves direct current (DC) to alternating current (AC) conversion through transistor switching.
This is the core mechanism, that enables the working of such a car. There are many more things, used in a gasoline engine car that need to be replaced or thrown out altogether, while building an electric car. Let me now provide you with a broad outline explaining the building of an electric car, by running a full scale transplant operation over a conventional gasoline powered car.
Building an Electric Car
Before you can begin, you will need a blueprint of the whole transplant operation ready for reference. A complete diagram of the circuitry, will have to be designed, before you start working. Get hold of books explaining their design and plan your own version, according to your specific requirements.
Step 1: Find an Appropriate Gasoline Car to Convert
First thing to do is to look for a gasoline car to be converted. The choice is entirely yours, but look for some car which has manual transmission and is roomy enough, as the batteries take up a lot of space. Do not go for a very old car and if you do, make sure its gear transmission and assembly is intact.
Step 2: Decide Upon Maximum Electrical Output Voltage
Next thing to decide is, at what voltage or power do you want the car to run. The range could be from 90 V to anything up to or more than 190 volts. The amount of voltage you decide to have, will tell you how many batteries you will require. It will also decide controller and AC motor specifications.
Step 3: Choose a Battery Type
Decide what kind of a battery you need. There are several options like, marine deep cycle lead acid batteries and high output sealed batteries. There are further more types to choose from, depending on the kind of electrolyte they use. They may be flooded, absorbed glass mat (AGM) or gelled batteries. The flooded ones are the cheapest but also the ones with the lowest output. Depending on what power you want, do the math and buy those number of batteries. Connect the batteries in series.
Step 4: Detach Unwanted Gasoline Car Components
Then begins the transplant operation of the gasoline car. Detach and remove the gas engine, the gasoline tank, the exhaust mechanism, the catalytic converter, the clutch and even the radiator.
Step 5: Begin Wiring According to Electrical Circuit Diagram
Before going for the electric wiring, draw a proper circuit diagram. Keep the manual transmission intact and attach a motor to it by using an adapter plate. You will require customized brackets to fix the motor in place.
Step 6: Build a Reduction Gear Set
The electric motor requires a reduction gear which will customize the gear mechanism for maximum efficiency. This can be achieved in two ways. Either build a new customized reduction gear or permanently fix the existing gear system into first or second gear. The first option is better but costly, the second is cheaper.
Step 7: Mount Controller and Batteries
Then mount the batteries and controller. The controller that is normally used is the same as that used in the forklifts. Smartly place the batteries by using space economically. Strap them and bracket them in place.
Step 8: Begin Wiring the Installed Components
Then comes the wiring part of the operation. Connect the controller and the battery to the motor and to each other by using high power cables. If it so happens, that the original car had a power steering mechanism, then install a separate motor for it.
Step 9: Install Air Conditioning, Compressor and Heater
If the car has air conditioning, you must mount another motor for working its compressor. A vacuum pump must be installed to operate the brake booster. Next, a small electric water heater must be installed into the heater core to drive the heating mechanism.
Step 10: DC-to-DC Converter Installation and Wiring of Accessories
To power all the accessory batteries, a DC-to-DC converter must be installed. You don't need the gas gauge anymore! Replace it with an appropriately calibrated voltmeter, which shows the charging level of the batteries in your car. Connect the accelerator pedals to controller with a potentiometer in the middle, as a connection link. The other accessories like car lights need to be rewired to the new battery set.
Step 11: Install Power Relay Mechanism
The pre-existing reverse gear in the manual transmission, can now be operated by the AC motor. The gear changing mechanism that is the gear stick, must be replaced by an electric switch. Last but not the least, one has to install a relay switching mechanism that connects or disconnects the car from its battery pack.
In short, it is the switch that turns the car 'on' or 'off'. The relay will have to be a high powered one, that can switch off the car at high voltages without sparking. Then connect your ignition switch to the relay, so that the relay is operated through the ignition switch. Install a separate charging mechanism for the car batteries. Put a charging socket on car exterior and wire the charging mechanism to it.
Step 12: Testing Phase
If you manage to pull all these things off, then your car is at least ready for testing. Test every part of assembly, individually. Test the operation of the controller, in synchronization with the accelerator pedal. Once you finish the stage testing, you are ready for the test drive. Once that goes successfully, you are ready for a smooth pollution free drive in your very own electric car!
The total cost for this whole procedure including all the supplies could be around US$10,000 or more. Price may vary according to the quality of the individual parts you buy. Once you build one, in the future, to go for a long drive, just plug in the power cord, charge your car and you are ready to go.