Just like anything in life, there are some obvious risk factors associated with working on a Do It Yourself (DIY) electric car. But these can be taken care of by adopting some simple homemade safety measures.
For example the electric shock, which is the most common hazards encountered in pure electric cars, can be easily avoided with a little precaution. A conventional automobile with an internal combustion engine is powered by gasoline therefore safety precaution should be taken to avoid any sparks or fire from the car. The same precaution should be taken with an electric vehicle (EV) which runs on electricity.
Here’s what you should do when working on a homemade electric car. Make sure that no connections from the batteries are left exposed where it may come in contact with your hands or tools. Put protective covers and tag all high voltage cables. Like the circuit breaker boxes, all good quality EV conversions should be installed with relays, fuses, and the connections should be inside a box as a safety measure.
Working With Battery Bank
Here’s a safety precaution you can take when working with the batteries on an EV. Use a small spanner when you are working with batteries in order to avoid accidentally connecting both the terminals. For further safety, you should insulate the handles of the spanner.
All deep cycle batteries for your electric car have two terminals. It has high voltage flowing from one column to the other. To avoid any bridging between both sides by accidental dropping your tools, placed a tall layer of insulation between the two columns of batteries. This simple step would greatly reduce the chances of any short connection.
Any high voltage connection on your EV should be clearly marked and segregated at a safe distance from the other electric systems of the car. Whether, electronic or mechanical, at any moment there can be compartment failure.
A provision for disconnecting the high voltage line when it is not in use is the basic feature of a good circuit design. With a view to implement some safety measure your can opt for an Anderson connector.
The Anderson connectors are designed provide a quick disconnect for power distribution systems. As an additional safety measure, some people use a circuit breaker that has a mechanical cable extending into the passenger compartment. This ensures a faster emergency disconnect.
When the “ignition key” is off, the high voltage should be disconnected. This is achieved by connecting a heavy duty relay to the ignition key.
Another relay is hooked to the accelerator pot box in the engine compartment to disconnect the high voltage whenever the accelerator is released. Thus, in case of emergency, whenever you turn the key off, or release the accelerator, the high voltage system gets disconnected automatically. For additional safety, to put off the relay at the event of any probable collision, you can attach an inertia switch to this circuit.
Above all, it is very important to follow some good work habits while you are working with your electric car conversion project. Everyone working in the electronics department in the army is supposed to work with one hand inside their pockets. This measure prevents the flow of electricity from one hand to the other hand through the chest. They also wear insulating boots as further safety measure.
All electrical equipments have safety disconnections. For further safety, grounding rods are fixed to the equipments. This ensures proper earthling and disconnection of the equipments. The entire emphasis was on the fact that all equipments are properly disconnected and good and safe working habits are followed.
DIY Electric Car Conversion Guide
Are you planning to convert a conventional automobile into a homemade electric vehicle? If you are, it is best you read up on the science of electric car conversion.
Before you begin your electric vehicle conversion project, check out the Convert2EV ebook by Les and Jane Oke. The Okes live a green lifestyle in Canada and one way of keeping their carbon footprint small is by using pure electric car. The Convert2EV manual was written based on their experience of retrofitting old gas guzzler into electric vehicle.
If you are planning to convert a gasoline driven car to run on electricity from your home garage, you have to know the entire key components in the EV. Each and every part in the system is important to make sure the electric vehicle is safe and functional.
The following is a list of 21 items of a homemade electric car.
1) Electric Motor (AC or DC) – The electric motor is the heart of the EV. Since the internal combustion engine (ICE) is removed, the electric motor will be the power plant to generate torque to propel the car forward.
2) Motor Controller – The motor controller is used to control the amount of electric current going into the electric motor. It is very similar to controlling the amount of fuel going into an engine therefore controlling the power output.
3) Manual Disconnect – A manual disconnect is basically a switch you use to cut off all the power in the system to reduce the chance of electrocution. You want to cut off the power when you are doing maintenance work on your EV.
4) Motor Adapter – A special metal plate custom made to fit the housing of the transmission unit. The motor adapter will be used to connect the electric motor to the vehicle transmission.
5) Main Contactor – This is the one main switch that can be used to totally disconnect all power flowing in the system.
6) Inertia Switch – The inertia switch will be automatically activated when there is an accident to disconnect the battery from the system.
7) Electric Charger – Used to charge the battery units of the electric car.
8) Battery Ends – The positive and negative ends of the battery where the cable terminal will be connected.
9) DC – DC Power Supply – A power supply that uses Direct Current to produce a variance of Direct Current.
10) Amp Meter Shunt – A measuring instrument used to measure the electric current flow in the EV circuit.
11) E – Meter – Used to measure the voltage output from the battery bank.
12) Fuses – Safety component for the electric circuit.
13) Throttle Box Control – Connected to the controller to regulate the power of the electric motor.
14) Battery Cable – Cables used to connect all the batteries together in series.
15) Cable Cutter – Heavy duty cutter used to cut and trim cables.
16) Lugs – Connected to the ends of the cables.
17) Cable Crimping Tool – A special tool used to crimp the ends of the cables to the lugs.
18) Vacuum Pump – Used to bleed the power brakes of the electric car.
19) Batteries – DC electric storage units used to power the electric motor. The type of battery suitable for EV conversion is the deep cycle type.
20) Battery Boxes – Storage and holding unit for the batteries. Acts as a temperature control and safety shield for the batteries.
21) Miscellaneous nuts and bolts – Used to hold all the parts together securely.
Gavin is from New Zealand and he has converted his 1987 Mitsubishi Tredia into an EV. His manual document his electric car conversion project.
Battery Racks For EV Conversion
Here’s a step that everyone has to go through when building an electric car from home. It is the process of making the racks for the battery. Why do we need battery racks for our EV? The simple reason is to hold the batteries in place.
As you may already know, a homemade electric car would need from 10 to 15 units of battery. On a full charge, your EV would able to travel up to 60 – 100 miles before it has to be recharged. With that many units of battery on board, you want to make sure the batteries do not slide from side to side when you accelerate or take a corner with your EV. That will be very hazardous!
Fitting The Battery Racks
Before you start making the racks, it would be a good idea to do some fittings. The type of battery recommended for electric cars are deep cycle battery. Now, how do you fit all the batteries in the electric donor car? Lets start with a mock fitting.
What you want to do is find free spaces in your EV to place the battery. Take a few pieces of cardboard paper and make it into a box that is the same size (equal width, length and height) with the battery you want to use. Make about 15 cardboard boxes. This is important and you will find out why.
The idea is to fit all the cardboard boxes into your electric car. Fit the boxes into the engine compartment area. Try to put them next to each other. Put a couple of the boxes into the booth at the back. If you need more space, place the boxes at the back seat.
The cardboard boxes that you’ve made will represent the actual space needed for your deep cycle batteries. If all the boxes fit, you know for sure all the batteries will fit.
Making The Frame
Now that you know where to place the batteries, your next step is to make the frame of the rack. The best material to use will be “L” steel section. Cut it to size and weld them together. Drill some holes for the bolts and nuts. Finally, fix the rack securely to the body of your electric donor car. That should pretty much does it.
Check out the following video of Gavin Shoebridge of New Zealand showing how he pre-fit the cardboard boxes and then making the frame for the battery racks for his DIY electric car.