75% developed

Electric Vehicle Conversion

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An electric vehicle conversion is the modification of a conventional internal combustion engine (ICE) driven vehicle to battery electric propulsion, creating a battery electric vehicle. Much of the information in this article is also applicable to the design and construction of electric vehicles from materials and components, as is commonly done by hobbyists assembling kit cars with ICEs.

Electric Vehicle Conversion Index

  1. Technologies
  2. Powertrain
  3. Battery disposition, security, and wiring
  4. Auxiliary systems and control
  5. Chassies, suspension, and running gear
  6. High power electrical
  7. Controls, interlocks, indicators, and alarms
  8. Conversion of concrete vehicles
  9. Resources

Introduction and disclaimers[edit | edit source]

While some conversions of internal combustion engine (ICE) vehicles have been performed by major automobile manufacturers in the United States, all such programs have been terminated due to (to quote the manufacturers) "lack of consumer demand" for these vehicles. A few specialty rebuilders offer new or remanufactured conversions to satisfy a rather limited demand. The demand is low primarily due to the costs of completed vehicles, which are up to twice that of a comparable ICE vehicle. Some of these are built on new vehicles, purchased from the original equipment manufacturer but without the various ICE components.

This article is concerned mainly with the hobbyist conversion of ICE vehicles to electric propulsion. It is not intended to be a complete instruction manual, but rather a general guide to performing your own conversions and for purchasing or modifying an EV conversion. Some representative types of vehicle conversions will be presented.

For those not interested in conducting their own electric vehicle conversion, there are many electric vehicle conversions specialists throughout the United States.

In this article "electric vehicle" (EV) refers to various hobby conversions, not to high-end manufactured vehicles. Also, only technologies available to the hobbyist are considered in depth.

Branded products may be illustrated where such are commonly used in EV conversions. This should not be considered to be promotional or an endorsement, which otherwise might be considered to be in violation of Wikibooks policy.

Note the presence of hazardous materials and conditions that must be approached with proper precautions and procedures to avoid damaging, injurious, or even fatal consequences.

Why have an electric vehicle?[edit | edit source]

The greatest fans of electric vehicles are those who have obtained and used them. Owing to the fact that electric vehicles have not been promoted by the major manufacturers in the United States, this is a self-selected group, so their enthusiasm may be misleading. Fans point out the following:

  • Range is adequate if not the only vehicle in household or if long commutes are not required. Fans point out that most trips in non-commute vehicles are for shopping, school drop-off/pick-up, visiting, and other errands within a 10 to 20 mile (15 to 30 km) radius. Long range is simply not needed for such trips and an operating range of 30 to 40 miles (50 to 65 km) is quite sufficient.
  • Fueling at home requires but seconds to plug in for overnight charging followed by a few extra moments in the morning. Some find this to be more convenient than driving to obtain gasoline whose availability and cost is less predictable.
  • The homeowner can install on-grid solar photovoltaic rooftop power or residential wind generation and so produce most of the energy required for personal transportation with zero pollution. Since the vehicles can be charged during low demand times the photovoltaics provide a larger societal benefit by helping to satisfy local peak demand, greatly reducing overall pollution and reducing transmission line loads. Additional benefits can also flow to the user through time sensitive pricing/payback schemes, significantly reducing the cost of a system that will support transportation needs. Once a commitment to producing power is made it becomes an easy decision to commit to producing all household and local transportation power needs. Thus there is a societal benefit from electric vehicles beyond transportation.
  • Electric vehicles are quiet. Even if not completely silent, they do not produce the low frequency rumble that can easily penetrate household walls and windows.
  • Owners take pride in the non-polluting nature of their vehicles. Some point out that knowing that your vehicle is non-polluting quickly leads to a realization how stinky and noxious even modern, well tuned non-electric vehicles actually are — something that tends to be ignored when you are part of the problem.
  • Some EV fans with a left of center political bias or of a "green" inclination claim that when combined with household photovoltaics, electric vehicle users are not assisting (through their fuel purchases) despotic governments in oil-rich countries, nor the politically powerful companies that prepare and distribute their products, nor the politically powerful coal interests, nor the domestic politicians that serve and protect these companies and countries. Many electric vehicle owners and operators express great satisfaction in this aspect of electric vehicle use, even while acknowledging that this use can have only little effect on these matters unless adopted more widely and produced in greater quantities.
  • Some EV fans with a right of center political bias believe that EVs will free the country from foreign sources of energy to ones domestically produced. This can make a country less strategically dependent on non-democratic oil-rich countries like Saudi Arabia.
  • Some USA EV fans have accused the three major domestic manufacturers, General Motors, Chrysler Corporation and Ford Motor Company of deliberately sabotaging their own electric vehicle efforts through several methods: failing to market, failing to produce appropriate vehicles, failing to satisfy demand, and using lease-only programs with prohibitions against end of lease purchase. They also point to the Chrysler "golf cart" program as an insult to the marketplace and to mandates, accusing Chrysler of intentionally failing to produce a vehicle usable in mixed traffic conditions. The manufacturers, in their own defense, have responded that they only make what the public wants. Of the various electric vehicles marketed by the "Big Three", only the General Motors EV1 (manufactured by GM) and the Th!nk City (imported and marketed by Ford) came close to being appropriate configurations for a mass market. However, at the end of their programs GM destroyed its fleet, to avoid the continuing expense necessary to continue to provide maintenance and support for these vehicles. Ford's Norwegian-built "Th!nk" fleet was covered by a three-year exemption to the standard U.S. Motor Vehicle Safety laws, after which time Ford had planned to dismantle and recycle its fleet; the company was, however, persuaded by the Norwegian Government and others to not destroy its fleet but return them to Norway and sell them as used vehicles. Ford also sold a few lead-acid battery Ranger EVs and has allowed a small percentage of lease returns into a limited market (after crushing and destroying 90 percent of the fleet, without saving any components), and some fleet purchase Chevrolet S-10 EV pickups are being refurbished and sold on the secondary market.
  • Both Honda and Toyota also manufactured electric only vehicles. Honda followed the lead of the other majors and terminated their lease-only programs. Toyota offered vehicles for both sale and lease. While Toyota has terminated manufacture of new vehicles it continues to support those manufactured and is allowing for some institutional lease returns to be placed in the marketplace. It is actually possible to see a RAV-4 EV on the road but this is indeed a rare sight.

Why convert or purchase a converted ICE to get an electric vehicle?[edit | edit source]

In Europe and some parts of Asia vehicle buyers have the choice of ICE or electric - it is actually possible to obtain reliable, well engineered and road-worthy electric vehicles and to have them maintained by a dealer. Other than for a beginning market for Neighborhood Electric Vehicles (NEVs), is not possible in the United States for economic, political, and market-restraint reasons. Nor is it possible for a person to easily import a new electric vehicle from Europe or Asia. Certain restrictive safety regulations (such as the requirement for safety glass rather than tempered glass in windshields, airbag requirements, lighting regulations, plus the destructive testing by barrier collisions all operate to inhibit the use of offshore manufactured vehicles. In contrast there are few restrictions on the personal conversion of an ICE vehicle to BEV (battery electric vehicle). This anomaly is distinctly cultural in English speaking North America and is emblematic of a dichotomy in the American political psyche: On the one hand, social and political pressures force the government to protect consumers in the marketplace from exploitation by corporations and large corporations prefer legislation that restricts the entry of new players into the marketplace, while the preservation of individual freedom to tinker in one's garage or workshop is considered sacred, being in the spirit of great inventors such as Edison and the Wright brothers.

Note that battery technology is rapidly improving in cost/performance ratios due to the use of batteries in ICE-electric hybrid vehicles. The EV that is converted today will be upgradeable by future battery (and perhaps charger) replacement.

Recent history of the electric vehicle in California[edit | edit source]

Beginning in the 1990s, the California Air Resources Board was looking for a way to combat air pollution and when General Motors began work with their EV1 it caught the attention of the Air Resources Board (Jananne Sharpless, Who Killed the Electric Car Interview). They also saw that the state was spending over $5 billion on air pollution-related illness. There was also a study done in 1989 that reported one out of four 18- to 25-year-olds had severe to moderate lung lesions. The Resources board eventually passed a mandate that stated by 2003, 10% of all vehicles sold in the state would be zero emission vehicles (ZEV). Toyota, Honda, General Motors, Ford, and Nissan all built limited production runs of battery-powered vehicles. For a variety of reasons; some say lack of advertising from the original equipment manufacturers (OEMs), others say the lack of purchase (they were only available by closed-end leases); still others say that the limited production runs kept costs too high to make them affordable by the average buyer. Almost all of the leased cars were collected at the end of their lease and then destroyed, despite the protestations of willing buyers. The CARB charter was not necessarily intended to drive up the production of electric vehicles, but rather to reduce air pollution. The manufacturers successfully argued for changes to the rules. The CARB specifications were modified from zero emissions to an equivalent emission reduction by the mandated production of very low emission vehicles, SULEVs (SUper Low Emission Vehicles) — vehicles producing about one tenth the previously mandated emission levels. This effectively created a hole in the mandate, because the U.S. Federal Government is the only governing body allowed to "mandate" MPG; these are called CAFE standards, they also have not changed (until 2008) since the oil embargo of the 1970s. Later on, GM, followed by DaimlerChrysler and several dealerships, would sue CARB. It would not be until the Federal government would come on board, as well as the Bush administration, to help kill the electric car. Not much later, President Bush would commit more than a billion dollars to hydrogen fuel cells, while totally ignoring current and past 170-year-old EV technology, established by analysis to be far more efficient source-to-sink than the proposed hydrogen schemes.

Attitude[edit | edit source]

In general, you should not attempt to maintain and operate a "home made" electric vehicle unless you have some interest and perhaps at least modest skills concerning mechanical and electric devices. Such skills are difficult to come by in many states due to the generally low volume of shop and industrial arts classes in current intermediate and high school programs. However, if you are the kind of person who will at least take apart a malfunctioning small appliance, and can sometimes at least identify the problem (e.g., needs regreasing or new motor brushes) you should have little problem with maintaining an EV.

A professionally built conversion will often be designed to be ignored, being engineered, constructed, and tested to survive with only minor maintenance on the operator's part and regular charging, combined with a regular professionally performed maintenance schedule. On the other hand, a non-professional conversion will probably require regular inspections of details like battery and motor electrical and mechanical connections, security of auxiliary systems, and inspection of wires and cables for chafing and loose connectors in order to avoid more extensive problems. While these tasks do not require a large amount of time, this time is more than is usually required of a conventional internal combustion vehicle, where tasks such as oil changes can be purchased as a service.

Operating costs[edit | edit source]

The direct operating costs will generally be confined to expenses for tires, battery replacement, battery water (where required), and electricity for recharging. Although the cost of electricity for charging these vehicles is generally much less than the cost of fuel for ICE vehicles, the cost of battery replacement can be very high. In general, the overall cost per mile for an EV — including periodic battery replacement — may be greater or less that for a conventional ICE vehicle of similar size and performance, depending largely upon the battery type used. For example, if the cost of electricity is (US) $0.12/kWh, the battery pack costs $1200 to replace (a low cost based upon the lowest cost technology), and lasts 20,000 miles (an optimistic number when using lead-acid batteries), and the vehicle uses 400 Wh/mile (a rather high number), the combined cost per mile will be ($960+$1200)/(20,000 miles), or less than $0.11/mile, comparable to an ICE vehicle getting 25 mpg at a fuel cost of $2.75 per gallon. This does not count avoided costs, such as engine oil changes (about $0.01/mile), smog inspections (about $0.002/mile), and various repairs required to maintain smog certification (which can be costly on an older ICE vehicle, probably between $0.005 and $0.015 per mile ), so the costs are currently roughly comparable at current fuel prices. With more expensive gasoline or the use of more expensive but longer lasting batteries, the costs further favor the electric conversion in the long run.

Since converted vehicles are usually of an older vehicle, such vehicles may need other maintenance due to accumulated wear, perhaps wheel bearings, brakes rotors or drums, brake pads or shoes, suspension bushings and the like, and other components that are not usually replaced, but keep the vehicle up to date and show pride in ownership such as upholstery, door seals, and body paint. Such work is generally not cost effective in an ICE vehicle if performed by hire, while an interested hobbyist may do much work at quite modest cost and obtain substantial enjoyment in learning and performing various craft skills.

While a worn ICE vehicle of comparable condition would be simply scrapped, you will likely want to maintain and even improve your conversion, so you should consider maintenance (and even improvement) expenses to be a normal part of maintaining an older vehicle. A more common vehicle may be cheaper to maintain when in the seven to twenty year age range than a rare, special interest, or very old vehicle due to the availability of low cost usable parts from automotive recycling yards. Some special interest vehicles have enabled the creation of a robust secondary parts market, although such vehicles are generally best left as ICE vehicles, unless especially suitable for conversion to electric power.

Skills needed[edit | edit source]

A wide range of skills is needed by a converter of a vehicle. Fortunately, there will often be fellow EV enthusiasts in an area that are willing and able to assist the novice builder. Although skill is needed but there should be a willingness along with a team of professionally qualified engineers.

Automobile survey[edit | edit source]

A builder should be able to identify problems in a potential conversion vehicle. These are the same skills required to identify and purchase a good used ICE vehicle and are especially useful if a conversion (complete or partial) is purchased from another builder. Note that it may be possible to purchase a used EV conversion that only needs batteries - the owner may want to build another vehicle using the proceeds from the sale of an earlier conversion but not wish to invest in new batteries for a vehicle about to be sold. A careful survey of such a vehicle will go beyond that stated above as it is very important that latent electrical defects be identified and corrected, e.g.: the presence of chafing points in the electrical system that could lead to short circuits and an awareness of the possible necessity for the addition of primary or secondary electrical and operational safety equipment and circuits.

Basic mechanics[edit | edit source]

A builder should be able to fabricate small brackets for mounting sensors, switches, and relays. This can be done using simple hand tools - a small vice, hacksaw, shears, hammer, pliers, and various drills and files.

Machine shop skills[edit | edit source]

Most machining requires expensive equipment and extensive skills. Machine shop skills will not be needed if the converter can obtain "off the shelf" components (components made to order from known specifications). In the case of exotic conversions the converter may have to have specialized work done locally, or ship the transmission to a specialty vendor. The more machine shop skills a builder has the more work that builder will be able to perform, and will be more skilled at selecting professional help. Creation of the motor coupling and the motor to transmission adapter usually require skills and experience of a high order (a typical automotive machinist will not usually be able to perform the work satisfactorily). A knowledgeable converter will be better able to judge the qualifications of the machinist to be employed, and a cooperative machinist may be willing to allow the converter to perform some of the lower skilled and lower risk tasks. It is also important that the machine shop tasks be well planned out and broken down into the component subtasks, something that a converter of modest machine shop skills will be able to do. Work in a machine shop may be done at fixed price (in which case the enumeration of tasks will aid in bid preparation) or performed using an hourly rate, in which case the estimate will be more accurate. For an exotic conversions where components must be designed a good relationship with a cooperative machine shop is essential to completing a successful and cost-effective project.

Welding[edit | edit source]

For conversion of a unit body vehicle it is especially important that the batteries be well secured. This is typically done by creating racks from angle steel stock or boxes from sheet metal welded into forms suitable for the batteries and vehicle. These racks or boxes are then welded to the unit body or secured to the vehicle's frame (if accessible). This requires care in avoiding warpage of the primary vehicle structure . For popular conversions it is possible to obtain manufactured racks designed for a pre-engineered layout, so this skill may be considered optional but dependent upon the vehicle selected for conversion. For light truck conversions with in-bed batteries no welding is necessary - all retention may be done with appropriate bolted hardwood components. Welding additionally requires special attention regarding the choice of base metal, fillet, type and size of weld. The weld size must be calculated such that it carrys the load with least weld thickness.

Automotive mechanics[edit | edit source]

The ability to remove, disassemble, rebuild, and install major ICE components such as transmissions, engines, and suspension components is useful but may be performed by a specialty conversion shop. The builder–owner should be especially cautious in the employment of ICE auto mechanics for these tasks as they may be unfamiliar with specialized EV procedures and requirements.

Basic electrical[edit | edit source]

A builder should be sufficiently knowledgeable about basic electricity to safely work on household and EV electrical systems. Note that an EV pack can provide extremely high currents, which can rapidly heat wires or misused tools, causing burns, and that batteries so overloaded can explode with consequent hazards of acid and toxic materials. Most traction packs and the associated high voltage accessory wiring (heater and twelve volt converter) supply or use potentially lethal voltages. Specific electrical arrangements are used to minimize the hazards present and it is important that the builder/operator observe proper precautions and maintain the equipment in a safe configuration.

Basic electronics[edit | edit source]

While the systems used in EV safety are not exotic, the builder should have sufficient skill to design and implement basic relay and diode logic for control and alarms. The smaller relays needed may be obtained at a local electronics supply shop or through an EV parts supplier. Some specialty components are obtained from EV parts suppliers or sometimes from automotive parts recyclers.

Application[edit | edit source]

Electric vehicles (EVs) are appropriate for short to medium range commuting. Longer ranges are possible if charging may be obtained at both ends of the commute.

EVs are appropriate for local errands where long range is not important. While Neighborhood Electric Vehicles (NEVs, essentially enhanced electric golf cars) are available from several manufactures, such vehicles are not considered here for hobby conversion as they are readily available from manufacturers and are not suitable for most suburban locations (although they may be well suited for operation in some urban environments and many self-contained communities).

Vehicle[edit | edit source]

Typical firewall components in a light truck

While almost any vehicle can be converted to electric power, one should be cautious about converting a vehicle simply because it is available (such as a family vehicle with a non-functioning engine). One should first consider the performance envelope that is both desired and affordable (see below) and then find a suitable vehicle that will satisfy these needs when converted. A good used vehicle in running condition may be a better choice than a vehicle with a major defect, as one can test the running components such as transmission, differential, suspension, and other components by road test. If the parts to be removed are in good condition it may be possible to obtain a good price by selling the engine while it can be demonstrated in the vehicle. A purchaser will thus have some confidence in the quality of the engine and may be willing to pay more than for one of unknown quality that has been removed from the vehicle. A later model may be available with advanced safety features and better brakes than would be available on a fifteen or twenty year old vehicle.

Performance envelope[edit | edit source]

Charger, controller, and vacuum components in a light truck, garden tractor battery to right of vacuum pump

As a minimum, an EV conversion should have sufficient performance so as not to impede conventional traffic operating within the speed limits of the roadway. This does not mean that it is necessary to obtain a level of performance equivalent to an ICE vehicle, although a short range performance vehicle may be constructed which will significantly outperform ICE vehicles below 30 mph (50 km/h).

Some designers point out that a specific type of electric vehicle offers comfort, utility and quickness, sacrificing only range. This is called a short range electric vehicle. This type may be built using high performance lead–acid batteries, but of only about half the mass that would be expected to obtain a 60 to 80 mile range. The result is a vehicle with about a thirty mile range, but when designed with appropriate weight distribution (40/60 front to rear) does not require power steering, offers exceptional acceleration in the lower end of its operating range, is freeway capable and legal, and costs less to build and maintain. By including a manual transmission this type of vehicle can obtain both better performance and higher efficiency than the single speed types developed by the major manufacturers. Unlike the converted golf carts used for neighborhood electric vehicles, these may be operated on typical suburban throughways (40 to 45 mph or 70 km/h speed limits are typical) and can keep up with traffic typical to these roads and to the short on and off segments of freeways that are common in suburban areas.

Operating costs vs. capital costs[edit | edit source]

Relative to an ICE vehicle an EV can offer substantially lower cost per mile in some applications but not all. An ICE can be very cheap to buy and maintain (until old and worn) but expensive for purchase of fuel and for "smog" inspections and oil changes.

An EV can be expensive to build and to replace batteries, yet quite inexpensive to operate if the cost of electricity is low. An EV is especially attractive if a homeowner has installed sufficient net metering photovoltaic (solar electric) panels, particularly if the net metering applies time of use rates.

Vehicle types[edit | edit source]

Novelty vehicle[edit | edit source]

At the 2005 Stanford University EV Gathering

Above: Bob Schneeveis [1][2][3] demonstrates his Silver Sofa to the delight of his passengers. This can spin rapidly in place like a carnival ride and its batteries are recharged by the solar panels.

A novelty vehicle or an electric powered art car may not be suitable for on road use. Applications include electric vehicle show demonstrations, parades, parade floats, float towing, and eclectic off-road gatherings such as Burning Man.

Shoebox racer[edit | edit source]

A prelude to larger vehicles, intended for the education of middle school students, these are fabricated from a standardised box of components, with the overall design and gear ratios determined by the builder. A building team will typically consist of two students and an adult advisor.

Electric cart[edit | edit source]

Suitable for educating youth in the technologies of electric vehicles, technically advanced versions of the cart can exhibit high efficiency in energy use and are a natural prelude to later developing pure solar electric racing vehicles or the conversion of ICE vehicles to electric drive. Speeds are typically limited to about seven MPH so a running adult can overtake and stop a vehicle. Some classes allow a great freedom in design by having a class first disassemble the previous constructions, returning components to appropriate bins. This disassembly task informs the students on design methods and equipment assembly. The students, in small teams, then design and construct new vehicles.

Tour del Sol[edit | edit source]

The ultimate in efficiency is exhibited by solar powered electric cars with highly refined chassies, electrics, and aerodynamics. These are designed and assembled by college teams with the support of various businesses, especially those involved with solar power, batteries, electric propulsion, or automotive manufacturing. Competitions are traditionally biennial, with the most widely recognized event being the World Solar Challenge in Australia, an 1800 mile race from Darwin to Adelaide. In the North American Solar Challenge teams race 2500 miles from Austin, Texas through Winnipeg, Manitoba finishing in Calgary, Alberta.

Electric bicycle[edit | edit source]

An electric bicycle is a class of bicycles that are fitted with an electric motor. Often they are powered by rechargeable batteries however some experimental electric bicycles run directly on or recharge their batteries via solar panels, fuel cells, gas generators or other alternatives energy sources. Some experimenters have even used super capacitors to store energy. Using an on-board generator may impact the legal jurisdictional definition of an electric bicycle. A few types of electric bicycles are able to re-capture energy from braking and can re-charge the batteries while braking or travelling down hills (regenerative braking). With the advent of newer technology further features can be expected.

Some electric bikes have features where the motor can move the bicycle by itself if the rider chooses not to pedal, while others require the rider to pedal at all times. (see the Wikipedia article motorized bicycle).

The conversion of a bicycle to electric power is probably the lowest cost means of learning conversion methods. Battery packs are usually lead acid gel cells since these are available in small sizes suitable for this application. It is also practical to experiment with more expensive battery types since only a small pack is required. It is possible to repurpose battery packs and chargers intended for powering toys and similar small electrical devices.

Electric Scooter[edit | edit source]

Scooter

Not typically suitable for on the road use these may be configured for either standing or sitting use

Electric motorcycle[edit | edit source]

Motorcycle

A specialty niche, this can offer an opportunity to build a relatively low cost electric vehicle. Most of these use a two wheel configuration, although the two types of three wheel vehicle (and sometimes four wheel vehicles) are classified as motorcycles in many jurisdictions if their weight is sufficiently low (typically around 1000 pounds maximum). If a tricycle layout is employed the single wheel should be at the back, with normal automotive type front wheel steering, as the single wheel forward type is notoriously unstable in handling.

Economy coupe[edit | edit source]

A light vehicle can make an excellent choice if care is taken in component selection and placement and use restrictions are accepted. It is possible to obtain conversion kits for some popular light vehicles, most notably the rear motor, rear drive Volkswagen "Beetle", its "Type 3" evolution, and its successor, the front motor/drive VW "Rabbit". One should not expect to convert such a vehicle and then use it to transport four full size (or oversize) adults - the cars simply do not have the safe load carrying capacity for that. Instead, count on simply removing the rear seat to obtain space for light luggage. Rear wheel drive vehicles are especially suitable for high performance applications as the weight transfer due to acceleration will increase the traction on the driven wheels.

By converting a light vehicle it is possible to use a smaller motor, which both weighs and costs less than a larger motor. Lighter overall vehicle weight will reduce power consumption in start and stop traffic and so increase range in many practical driving conditions.

(At least one commercial converter, Solectria, has converted the front wheel drive General Motors Metro for electric use, creating the Solectria Force.)

Compact sedan or coupe[edit | edit source]

A compact sedan, compared to a subcompact, may have better load capacity and more room for battery placement. But, it is also heavier, and will generally have higher wind drag. This means, compared to a subcompact, they will require larger and more expensive motors, a more expensive controller, and more batteries ( higher weight and cost) . Some commercial EV Conversions use vehicles in this size range. One example is a 1992 Honda Civic (http://www.austinev.org/evalbum/542.html). In this conversion, the back seat was retained, and there is still enough room to sink nine flooded lead acid batteries low in the trunk where the spare tire was located, as well as another nine batteries under the hood. With suspension modifications, (increasing shock length & spring rating), one will want to make certain that the vehicle is below GVWR to avoid an illegal and dangerous situation. The car should never be driven if the total vehicle weight is above the GVWR, or if either axle weight is above the maximum designed load for that axle. ( This is typically listed in the glove box, or on one of the door sills of the car)

Full size sedan[edit | edit source]

Full size sedans and minivans are generally considered to be less attractive candidates for EV conversion than smaller cars. It may be easier to obtain upgraded components for some smaller vehicles, since these may be used for sports racing (particularly autocross). Starting with a heavy vehicle and adding batteries will result in poor performance in acceleration, handling, braking, and economy of operation.

Sports car[edit | edit source]

For a person interested in sports car performance a satisfying conversion will likely lead to a number of difficulties in such details as battery disposition, as such vehicles generally have available space distributed in small volumes around the vehicle. This leads to complexity in securing and wiring batteries. Such vehicles can offer stunning performance in the lower speed ranges owing to light weight and rear wheel drive and may also offer good range from their superior aerodynamics.

By far the most often converted sports car is the Porsche 914 from the early 1970's. An unusually robust chassis, combined with a large interior storage volume for batteries has made this the vehicle of choice for many successful conversions.

Light truck[edit | edit source]

Light trucks are especially suitable for hobbyist conversion owing to the fact that it is easy to locate batteries remote from the passenger compartment and there is a good load handling capacity for the use of heavy batteries such as the flooded lead-acid batteries commonly used in golf carts. Light trucks also offer substantial utility in use simply because they are trucks. Even if a portion of the weight capacity is removed by the presence of batteries within or below the cargo bed, much of the spacial utility remains. A light truck is highly recommended as a first conversion effort owing to the simplicity of component layout. Furthermore, a light truck (being a utility vehicle) can reasonably be maintained to a lower level of cosmetic standards - paint and body work may be repaired to a lower standard of fit and finish than would be expected for a sedan, coupe, or sports car. (A simple light truck conversion example: http://www.campbellot.com/electric-s10/.) Light trucks of the early 21st century have outgrown their original design envelope, being made far taller and more bulky then needed. The last small light truck marketed in the early 2000s was the Nissan Frontier, now, in its current incarnation, "pumped up" with additional bulk and an unstable high center of gravity. The Toyota Hilux, while still manufactured, is not marketed within the USA. The most suitable light trucks for conversion are built on frames, and date from 1975 to the late 1990's and are almost all import brands.

Hotrod[edit | edit source]

While this type of vehicle is usually made to be a "street legal" performance machine it may also be developed for occasional use as a drag racing vehicle. The leading vehicle in this field was a Mazda RX-7 ([4]) sports car converted from rotary engine to electric. This vehicle can outrun Dodge Viper sports cars in quarter mile drag races. Faster still is John Wayland's White Zombie ([5]). This conversion of a 1972 Datsun 1200 sedan is currently the world's quickest & fastest Street legal car(in the 1/4 mile, per NEDRA).

Autocross racer[edit | edit source]

EVs may prove to be especially suitable for autocross contests as low speed acceleration is especially important to success in this type of racing. Specific classes for electric autocross (called "electrocross" )are being introduced in some venues. Vehicles for these will typically be economy car conversions or custom built chassies but with excess rear weight bias to allow agile handling under the control of an experienced driver (such rearward balance may be dangerous for everyday use).

Drag racer[edit | edit source]

Intended only for specialized straight line quarter mile (acceleration) racing this type of vehicle is used only "off road" at specialized "drag strips".

High speed straight line racer[edit | edit source]

Even more specialized than the drag racer this is intended to obtain high speeds on long, straight, and flat raceways, such as the dry lakebeds found in locations such as the Bonneville Salt Flats

Custom chassis[edit | edit source]

Suitable for a builder who is capable of constructing a kit car, with good abilities and equipment in machining and welding this can result in a unique vehicle. It is especially suitable for the construction of a lightweight vehicle that can offer exceptional performance.

Other trucks - full size and most SUVs[edit | edit source]

These are rarely converted due to their excessive weight, and inefficiencies (namely due to poor aerodynamics). To make the situation worse, many modern trucks/SUVs continue to get bulkier and heavier . As a direct result, the payload carrying capacity of the vehicles goes down. Such a trait is not desirable because it limits the weight of the battery pack that can be carried, limiting the maximum battery-to-vehicle weight ratio that could be achieved for the vehicle when converted to an EV. For a given battery type, reducing the battery-to-vehicle weight ratio always results in reduced vehicle range per charge. However, despite these mostly unavoidable limitations, several SUVs and larger trucks have been successfully converted to electric power by hobbyists. Some examples include the "Gone Postal" van converted to an EV racer by Roderick Wilde and Suckamps EV Racing, the 1971 Land Rover EV converted by Wilde Evolutions, and the 1988 Jeep Cherokee EV converted by Nick Viera.