How to Make an Electric Car for a Science Project

The main key for building an electric car for a science project is the weight to power ratio. A vehicle will need to be light enough to be able to be moved by a relatively small electric motor. The smaller the motor, the less power required to the electric motor, and subsequently, the fewer batteries needed.

Things You'll Need

• Light gasoline car
• 24 volt electric motor
• 24 volt batteries
• Electrical control components

Instructions

Don't Build it, Convert it

1. When building an electric car you don't need to reinvent the wheel so try to use an existing vehicle and simply do a conversion. Find a light aerodynamic gasoline car and take out the engine assemblies. This on its own will significantly reduce the weight.

2. There are conversion kits available online and since the cost of these is upwards of a few dollars, then for a high school project it is best to stick to the cheapest ways possible. Surplus aircraft starter motors are 24 volt motors and these are becoming popular to use in small car conversions.

3. Remove the combustion motor and replace it with a 24 volt motor. These are available at any aircraft junk yard or Air Force surplus store. When obtaining the motors you should take the opportunity to buy a number of 24 volt aircraft batteries as well. The room under a small car's hood would probably hold 4 batteries, once the motor is in place.

4. Mount the electric motor so that it turns the gearbox of the car. The gears are really unnecessary in this case, unlike with an electric motor you can start in top gear and it will have no ill effect. You should, however, leave the gearbox in situ as removing it will just increase the work involved in converting the car.

5. Build a bank of batteries to power the engine with the applicable switches and rheostats to control the speed. Connect the rheostat to the accelerator pedal and it will function as well as the gas pedal. Make sure you connect the batteries in parallel as this will make them last longer. To connect them in parallel connect positive to positive and negative to negative, and then to the control rheostat and then the motor, thus the power output will still be 24 volts but it will last significantly longer.

Tips & Warnings

• At this point the car should be able to be driven. Remember once the batteries run down they can be recharged much like any other battery but this will take time.

• Make sure the vehicle is roadworthy.

References

• Electric Car

Resources

• Home Made