This page contains excerpts from my eBook
"Electric Vehicle Conversions"
Preface
Starting a conversion of a car or truck requires some equipment not usually found in ones garage. Basic wrenches, metric and SAE, are a must. A good socket set of 1/4 inch drive, 3/8 inch drive, and 1/2 inch drive will be needed. A small bench grinder and a hand held grinder will be used if you plan to cut and weld your frames. Also an abrasive cutoff saw to cut pieces of material is a must. An assortment of C-clamps, and one or two vise grips will be needed if your do your own fabricating and welding. (Harbor Freight Company is a good source for inexpensive tools) A bench vise will come in handy for holding parts for grinding, drilling, and also for welding.
The Preface goes on to explain many of the tools needed for the conversion.
Chapter One - Donor Vehicles
The choice of a vehicle to convert is dependent on your needs for passenger and/or other cargo. The conventional wisdom today is to use the lightest vehicle which meets your needs, because it will require less power to move and therefore less batteries. Manual transmissions are used exclusively for conversions because automatic transmissions are designed for a constantly running engine. The electric motor stops turning when the car stops and will not power the transmission correctly. Also the shift points on the auto transmission are much to low for electric motor drives as they perform better at high revs. Almost any car or truck can be converted with todays technology, as the following chapters will explain..
The balance between light weight and capability to handle the extra weight of the battery pack creates a "catch 22" effect, where the lightest car's suspension and construction will not handle the extra weight and will need to be beefed up a little. I believe the small pick-ups offer a better platform to mount the batteries because of the sturdy frame and heavy springs used in their construction.
In the following chapters I will talk about motors, battery types and voltage needed for your car. The weight of the donor vehicle will determine the requirements for the motor and batteries.
Chapter Two - Types of electric motors
When converting to electric drive there are two types of motors available - DC and AC.
DC drives are less expensive initially, and are quite suitable for any size vehicle. This is the type motor I chose for my conversion.
AC drives are more expensive and are sold with a motor controller designed for each motor and voltage expected.
Chapter Three - Controllers
Motor controller is needed to accept the drivers throttle command and convert it to a controlled voltage to the motor. These are very high amperage devices, handling up to 2000 amps of current between the batteries and the motor. Voltages typically are between 72 volts and 300 volts. For the DC motors there are several companies selling controllers for the US markets.
AC controllers are mated to the motor, because there are more details to monitor and control. This is not a bad thing, it is just the nature of the design. All the AC motor suppliers will have advice on what controller goes with their motors. Many have built up packages that mount on specific cars and trucks, taking the guess work out of the conversion.
Chapter Four - Batteries
When choosing batteries for a conversion vehicle many factors must be considered. At the time of my conversion lead acid type "golf cart" batteries were considered the best power to cost choice. The group of 6 volt batteries at a 20 hour rating of over 200 amps gives plenty of power available but has a weight disadvantage. This was the direction I went because the cost fell within my budget.
Chapter Five - Other parts needed to make it run.
There are many parts that will be needed to convert a vehicle for battery power. I am going to try to list them so that the reader can be aware of them. I have writen a description of each component and how it is used.
Chapter Six - Getting started
One important step to remember before you disable the vehicle. If it has a functioning air conditioning system you need to take it to an A/C shop and have them remove the freon charge. That way you don't risk opening a pressurized line, and you are saving the atmosphere from greenhouse gasses. In my case I had to completely remove the pump and all the lines during the conversion, Some cars might allow the lines to be tied over to one side without disconnecting them. This is preferred but not always possible.
My first inclination was to start disconnecting everything from the old engine and pull it out.
The thing to remember is that some of the wires will need to used in the new configuration. There will be bundles of wires that attach all over the old engine, many of which are not needed. However during the engine removal tag every wire with tape marked as to what its function was. I made the mistake of pulling plugs loose without tagging them, and I was unable to locate some of the necessary wires later. Another problem arose when I tried to use the fans and A/C controls on the dash. I cut so many wires during the engine removal that nothing works the way it should. I recommend leaving all the wires and plugs as they were with the gas engine, just tape them up and tie them out of the way.
Chapter Seven - Battery Layout
If the donor vehicle is a pickup truck, which mine was, then there are two options for mounting the batteries.
The simple solution is to build a rack for them in the bed, up close to the cab. This keeps the weight ahead of the rear axle which then shares some of the load with the front suspension. The batteries then can then either be boxed to protect them, or a full bed cover could be used.
The second solution is to build racks which retain the batteries under the bed between the frame rails. This brings the weight down low, but will result in some of the batteries being mounted behind the rear axle. The truck then retains the function of having the bed to haul items.
Chapter Eight - Mounting the electric motor
The choice of vehicle will have a great influence on the motor selection and the mount consideration. A rear wheel drive car or truck will have more room in the engine compartment than a front wheel drive vehicle. There are several companies producing adaptors and motor mounts for conversions. All of the popular donor vehicles now have adaptors and motor mounts for standard shift transmissions..
Check with the following companies for adaptors and mounts before purchasing your vehicle.
http://www.canev.com/KitsComp/Components/Components.html
http://www.grassrootsev.com/catalog.htm
http://www.evparts.com/shopping/mainpage.php?id=3#Adaptors%20&%20Kits
Chapter Nine - Mounting the other components.
I then started designing the battery racks for the front and at the same time started to layout the positions for the motor controller, contactor, and charger. I retained the power steering pump and the A/C compressor (Florida!) so I had to also make new mounts for them. I used the motor mount that I had built as a base to weld angle pieces forming a box shape. Using the original engine casting that held the P/S and A/C pumps I determined where to locate the pumps so that they would be able to use the original hoses. They sit up high so it was not a problem avoiding the electric motor.
Chapter Ten - Starting up the vehicle for the first time.
When I completed the wiring I towed my truck to Ft. Pierce to have Steve Clunn (Grassroots EV) review everything that I had done and verify it was ready to start up.
Some of the things he checked can be done to find possible errors before they cause problems
What does the future have in store for us?
One thing that will affect the electric vehicle market is the price of gasoline. I have no idea where prices will end up, but I feel confident that they will continue to go higher. There is every reason to believe, even with the limited range of the battery powered cars today, that families with two cars can use an electric car for in town driving. If one car was a hybrid powered sedan and the other was a battery powered EV the demand for gas would get under control rapidly.
The future holds great promise for improvements in large format batteries for vehicle drive packs. Several technologies have emerged using Lithium Ion chemistry in a stable package. The lead acid cells may see a breakthrough in weight reduction which would make this a good choice for vehicle conversions. Other companies will discover new chemistries which we have not even heard of.
However I am enough of a realist to know that we must go with what we have now. If we convert our cars now, the battery companies will fill the demand with better technology. It may take a few years but our battery packs have a 3 to 4 year life anyway. I am hopeful that my next battery pack will be lighter and more powerful!
What about the price of the components? Today, as the demand slowly increases, the suppliers are having a difficult time keeping up with production. This is having an upward pressure on the prices, along with ever rising raw material prices. However the long term result is generally a reduction in prices as production ramps up and economy of scale kicks in.
I hope this preview has given you an idea of the scope of my book.
Payment is with Paypal or any credit card.
Thanks for your interest. Whether you buy my book or not, I hope you do convert or buy an electric vehicle!
Gerald Wagner
