Electric car

The Toyota RAV4 EV was powered by twenty-four 12 volt batteries, with an operational cost equivalent of over 165 miles per gallon at 2005 US gasoline prices.

File:DynastyEVSedan.jpg

The Canadian Dynasty EV 4 door sedan neighborhood electric vehicle.

The Indian REVA 2 door seen here in Malta. More REVAs have been produced than any other currently selling electric car. While in the UK it's a full blown EV, in the US it is allowed only as neighborhood electric vehicle with reduced top speed.

The electric car is a vehicle that utilizes chemical energy stored in rechargeable battery packs, and electric motors and motor controllers instead of an internal combustion engine (ICE).

Vehicles using both electric motors and ICEs (hybrid electric vehicles) are examples of hybrid vehicles, and are not considered pure electric vehicles (EVs) because they operate in a charge-sustaining mode. Hybrid vehicles with batteries that can be charged externally to displace some or all of their ICE power and gasoline fuel are called plug-in hybrid electric vehicles (PHEV), and are pure battery electric vehicles (BEVs) during their charge-depleting mode. Electric vehicles include automobiles, light trucks, and neighborhood electric vehicles.

Electric cars were among the earliest automobiles. They produce no exhaust fumes, and minimal pollution if charged from most forms of renewable energy. Many are capable of acceleration exceeding that of conventional vehicles, are quiet, and do not produce noxious fumes. Electric cars reduce dependence on petroleum and decrease or eliminate greenhouse gas emissions, depending on how their electricity is produced.

Historically, EVs and PHEVs have had issues with high battery costs, limited travel distance between battery recharging, charging time, and battery lifespan, which have limited widespread adoption. Ongoing battery technology advancements have addressed many of these problems; many models have recently been prototyped, and a handful of future production models have been announced. Toyota, Honda, Ford and General Motors all produced electric cars in the 1990s in order to comply with the California Air Resources Board's Zero Emission Vehicle Mandate. The major US automobile manufacturers have been accused of deliberately sabotaging their electric vehicle production efforts.

Electric cars are expected to be cheaper to make and maintain than internal combustion engine vehicles because they have many fewer parts. Using regenerative braking, a feature which is standard on many electric and hybrid vehicles, a significant portion of the energy expended during acceleration may be recovered during braking, increasing the efficiency of the vehicle.

In general terms an electric car is a rechargeable battery electric vehicle. Other examples of rechargeable electric vehicles are ones that store electricity in ultracapacitors, or in a flywheel.

Relation with hybrid vehicles

Vehicles using both electric motors and Internal Combustion Engines are examples of hybrid vehicles, and are not considered pure electric vehicles (also called all-electric vehicles) because they operate in a charge-sustaining mode. Hybrid vehicles with batteries that can be charged externally to displace some or all of their ICE power and gasoline fuel are called plug-in hybrid electric vehicles (PHEV), and are pure EVs during their charge-depleting mode. The coming Chevrolet Volt is of this type. If batteries cannot be charged externally, the vehicles are called regular hybrids.

History

Main article: History of the electric vehicle

1912 Detroit Electric advertisement

File:Ed d22m.jpg

Thomas Edison and an electric car in 1913 (courtesy of the National Museum of American History)

Electric car and antique car on display at a 1912 auto show in Toronto

Camille Jenatzy in electric car La Jamais Contente, 1899

The electric car was among some of the earliest automobiles — small electric vehicles predate the Otto cycle upon which Diesel (diesel engine) and Benz (gasoline engine) based the automobile. Between 1832 and 1839 (the exact year is uncertain), Scottish businessman Robert Anderson invented the first crude electric carriage. Professor Sibrandus Stratingh of Groningen, the Netherlands, designed the small-scale electric car, built by his assistant Christopher Becker in 1835.

The improvement of the storage battery, by Frenchmen Gaston Plante in 1865 and Camille Faure in 1881, paved the way for electric vehicles to flourish. An electric-powered two-wheel cycle was demonstrated at the World Exhibition 1867 in Paris by the Austrian inventor Franz Kravogl. France and Great Britain were the first nations to support the widespread development of electric vehicles. In November 1881 French inventor Gustave Trouvé demonstrated a working three-wheeled automobile at the International Exhibition of Electricity in Paris.

Just prior to 1900, before the pre-eminence of powerful but polluting internal combustion engines, electric automobiles held many speed and distance records. Among the most notable of these records was the breaking of the 100 km/h (60 mph) speed barrier, by Camille Jenatzy on April 29, 1899 in his 'rocket-shaped' vehicle Jamais Contente, which reached a top speed of 105.88 km/h (65.79 mph).

Electric cars, produced in the USA by Anthony Electric, Baker, Detroit, Edison, Studebaker, and others during the early 20th century for a time out-sold gasoline-powered vehicles. Due to technological limitations and the lack of transistor-based electric technology, the top speed of these early electric vehicles was limited to about 32 km/h (20 mph). These vehicles were successfully sold as town cars to upper-class customers and were often marketed as suitable vehicles for women drivers due to their clean, quiet and easy operation. Electrics did not require hand-cranking to start.

The introduction of the electric starter by Cadillac in 1913 simplified the task of starting the internal combustion engine, formerly difficult and sometimes dangerous. This innovation contributed to the downfall of the electric vehicle, as did the mass-produced and relatively inexpensive Ford Model T, which had been produced since 1908. Internal-combustion vehicles advanced technologically, ultimately becoming more practical than — and out-performing — their electric-powered competitors.

Another blow to electric cars in the USA was the loss of Edison's direct current (DC) electric power transmission system in the War of Currents. This deprived BEV users of a convenient source of DC electricity to recharge their batteries. As the technology of rectifiers was still in its infancy, changing alternating current to DC required a costly rotary converter.

Electric vehicles became popular for some limited range applications. Forklifts were EVs when they were introduced in 1923 by Yale[2]; many battery electric fork lifts are still produced. Electric golf carts have been available for many years, including early models by Lektra in 1954.[3] Their popularity led to their use as neighborhood electric vehicles; larger versions are becoming popular and increasingly ruled "street legal".

By the late 1930s, the electric automobile industry had completely disappeared, with battery-electric traction being limited to niche applications, such as certain industrial vehicles. A thorough examination into the social and technological reasons for the failure of electric cars is to be found in Taking Charge: The Electric Automobile in America[4] by Michael Brian Schiffer.

The 1947 invention of the point-contact transistor marked the beginning of a new era for EV technology. Within a decade, Henney Coachworks had joined forces with National Union Electric Company, the makers of Exide batteries, to produce the first modern electric car based on transistor technology, the Henney Kilowatt, produced in 36-volt and 72-volt configurations. The 72-volt models had a top speed approaching 96 km/h (60 mph) and could travel nearly an hour on a single charge. Despite the improved practicality of the Henney Kilowatt over previous electric cars, it was too expensive, and production was terminated in 1961. Even though the Henney Kilowatt never reached mass production volume, their transistor-based electric technology paved the way for modern EVs.

Battery powered electric concept cars continued to appear, such as the General Motors "Electrovair" (1966) and "Electrovette" (1976). At the 1990 Los Angeles Auto Show, GM President Roger Smith unveiled the "Impact" electric car, the precursor to the EV1, promising that GM would build electric cars for the public. Nine months later, the California Air Resources Board (CARB) mandated electric car sales by major automakers. In response, makers developed EVs including the Chrysler TEVan, Ford Ranger EV pickup truck, GM EV1 and S10 EV pickup, Honda EV Plus sedan, Nissan lithium-battery Altra EV miniwagon and Toyota RAV4 EV. Automakers refused to properly promote or sell their EVs, allowed consumers to drive them only by closed-end lease and, along with oil groups, fought the mandate.

Chrysler, GM and some GM dealers sued in Federal court; California soon neutered its ZEV Mandate. After public protests by EV drivers' groups upset by the repossession of their EVs, Toyota offered the last 328 RAV4-EVs for sale to the general public during six months (ending on November 22, 2002). All other electric cars, with minor exceptions, were withdrawn from the market and destroyed by their manufacturers. To its credit, Toyota not only supports the 328 Toyota RAV4-EV in the hands of the general public, still all running at this date, but also supports hundreds in fleet usage. From time to time, Toyota RAV4-EVs come up for sale on the used market and command prices sometimes over 60 thousand dollars. These are highly prized by solar homeowners, who charge their cars from their solar electric rooftop systems.

Present and future

As of July, 2006, there were between 60,000 and 76,000 low-speed, battery powered vehicles in use in the US, up from about 56,000 in 2004, according to Electric Drive Transportation Association estimates. There are now over 100,000 NEVs on US streets.

The Tesla Roadster, the first 650 of which are scheduled for delivery in 2008 uses Li-Ion batteries to achieve 220 miles per charge, while also capable of going 0-60 in under 4 seconds.

In 2004, several Silicon Valley entrepreneurs (Elon Musk, known for co-founding Paypal and founding SpaceX, and Martin Eberhard) started Tesla Motors. In 2006 they announced the production of the Tesla Roadster. The Roadster, the design of which is based on the Lotus Elise, uses Lithium-Ion batteries rather than the lead-acid batteries which had previously been predominant in small-maker BEVs. The vehicle uses 6831 li-ion batteries to travel 245 miles per charge, an equivalent fuel efficiency of 135 mpg (U.S.) (1.74 L/100 km), yet accelerates from 0-60 in under 4 seconds on its way to a top speed of 135 mph (210 km/h). Tesla is set to begin deliveries of Roadsters in early 2008. The company announced that production of the Roadster had officially begun on March 17th. The first Tesla was delivered on February 1, 2008.

Miles Electric Vehicles, the XS500 capable of 85mph with an estimated price around $30,000.

In December, 2007, Fortune media reported on eleven new companies planning to offer highway-capable electric cars within a few years. Aptera Motors plans to sell both electric and hybrid vehicles in late 2008. Mitsubishi will sell its iMiev EV beginning in 2009, with Subaru and ZAP Motors - Detroit Electric to soon follow.

In 2007, Miles Electric Vehicles announced that it would produce a highway-speed all-electric sedan named the XS500. The company anticipates that the XS500 will be available for sale in the U.S. in early 2009. The XS500 uses Li-Ion batteries.Rubin, Miles. "XS500". Retrieved 2008-04-15. Hargreaves, Steve. "XS500". Retrieved 2007-08-13.

In early 2008, Dodge announced the Dodge Zeo. While there are no official release dates or prices, they say it will be affordable to the average american. Dodge Zeo

Regulation in California

Since the late 1980s, electric vehicles have been promoted in the US through the use of tax credits. Electric cars are the most common form of what is defined by the California Air Resources Board (CARB) as zero emission vehicle (ZEV) passenger automobiles, because they produce no emissions while being driven. The CARB had set progressive quotas for sales of ZEVs, but most were withdrawn after lobbying and a lawsuit by auto manufacturers complaining that EVs were economically infeasible due to an alleged "lack of consumer demand". Most of these lobbying influences are shown in a documentary, called Who Killed the Electric Car?.

The California program was designed by the CARB to reduce air pollution and not specifically to promote electric vehicles. Under pressure from various manufactures, CARB replaced the zero emissions requirement with a combined requirement of a very small number of ZEVs to promote research and development, and a much larger number of partial zero-emissions vehicles (PZEVs), an administrative designation for a super ultra low emissions vehicle (SULEV), which emit about ten percent of the pollution of ordinary low emissions vehicles and are also certified for zero evaporative emissions. While effective in reaching the air pollution goals projected for the zero emissions requirement, the market effect was to permit the major manufacturers to quickly terminate their electric car programs and crush the vehicles.

Selected production vehicles

Further information: Category:Production electric vehicles

and List of production battery electric vehicles

Selected list of battery electric vehicles include (in chronological order):

Name	Comments	Production years	Number produced	Top Speed	Cost	Range
Baker Electric	The first electric car; it was reputedly easy to drive	1899–1915	?	14 mph 23 km/h	US$2300 or €1,700	50 mi 80 km
Detroit Electric	Sold mainly to women and physicians.	1907–1939	<5000	20 mph 32 km/h	>US$3,000 or €2,250 depending on options	80 mi (130 km)
Henney Kilowatt	The first modern (transistor-based) electric car and outfitted with modern hydraulic brakes.	1958–1960	<100	60 mph 97 km/h	?	?
Skoda Favorit ELTRA 151L & 151 Pick-Up	Czech-built (first electric car prog. for eastern block mfr.), exported to Europe and N. America. Lead acid batt. 15 kW·h pack nominal; 84 V system with regen.	1992-1994	<1100, perhaps 20 surviving	50 mph 80 km/h (limiter)	< US $20,000, without subsidy	50 mi 80 km
General Motors EV1	For lease only, all recovered from customers by General Motors and most destroyed	1996–2003	1117	80 mph 129 km/h	~ US$40,000 or €30,000, without subsidies	160 mi 257 km
Honda EV Plus	First BEV from a major automaker without lead-acid batteries. 24 twelve volt NiMH batteries	1997–1999	~300	80+ mph 130+ km/h	US$455 or €340/month for 36 month lease; or $53,000 or €40,000 without subsidies	80–110 mi 130–180 km
Toyota RAV4 EV	Some leased and sold on US east and west coasts, supported. Toyota agreed to stop crushing.	1997–2002	1249	78 mph 125 km/h	US$40,000 or €30,00 without subsidies	87 mi 140 km
Ford Ranger EV	Some sold, most leased; almost all recovered and most destroyed. Ford allowed reconditioning and sale of a limited quantity to former leaseholders by lottery.	1998–2002	1500, perhaps 200 surviving		~ US$50,000 or €37,600; subsidized down to $20,000 or €15,000	74 mi 119 km
Nissan Altra EV	Mid-sized station wagon designed from the ground up as the first BEV to use Li-ion batteries, 100,000+ mi (160,000 km) battery lifetime	1998–2000	~133	75+ mph 120+ km/h	US$470/month lease only	120 mi 193 km
TH!NK City	Two seat, 85 km (52 mi) range, NiCd batteries. Next generation vehicle production planned for fall 2007.	1999–2002	1005	56 mph 90 km/h		53 mi 85 km
REVA	Indian-built city car (sold in England as the "G-Wiz").	2001–	>1800	45 mph 72 km/h	£8,000, US$15,000 or €11,900	50 mi 80 km
ZAP Xebra	Chinese built sedan and truck	2006–	700+	36 mph 60 km/h	$10,000 or €7,500	20 mi 32 km
Tesla Roadster	650 scheduled for delivery in 2008, first one delivered February 1, 2008	2008–	1	130 mph or 210 km/h [5]	US$92,000 or €69,120 base price [6]	220 mi 350 km

Use

In the United States

I believe strongly that this country has to get off oil ... The electrification of the automobile is inevitable.

— Bob Lutz, GM Vice-Chairman of global product development, in Newsweek magazine

The following chart and table are based on Department of Energy tables on Alternatives to Traditional Transportation Fuels 2005, from table V1 and from the Historical Data. Figures for electric vehicles include Low-Speed Vehicles (LSVs), which are "four-wheeled motor vehicles whose top speed is between 20 and 25 miles per hour [32 to 40 km/h]...to be used in residential areas, planned communities, industrial sites, and other areas with low density traffic, and low-speed zones." LSVs, more commonly known as neighborhood electric vehicles (NEVs), were defined in 1998 by the National Highway Traffic Safety Administration's Federal Motor Vehicle Safety Standard No. 500, which required safety features such as windshields and seat belts, but not doors or side walls.

Number of battery electric vehicles in use each year (red), and year-to-year percentage increase (blue), per table at left

Battery Electric Vehicles in the United States
Year	Number
1992	1,607
1993	1,690
1994	2,224
1995	2,860
1996	3,280
1997	4,453
1998	5,243
1999	6,964
2000	11,830
2001	17,847
2002	33,047
2003	47,485
2004	49,536
2005	51,398
Average growth	30.5%

Israel

Israel's Shai Agassi has reached agreements with Renault-Nissan and the Israeli government for a plan called Project Better Place to install recharging and battery replacement stations nationwide and put 100,000 electric cars on the roads beginning in 2011. Israel is considered a practical choice for the first large-scale use of electric vehicles because 90 percent of car owners drive less than 70 kilometers per day and the major cities are fewer than 150 kilometers apart.

Comparison to internal combustion vehicles

Tzero an older model electric vehicle on a drag race with a Dodge Viper left behind

Electric cars have become much less common than internal combustion engine vehicles (ICEV). Therefore, it is often helpful to consider many aspects of BEVs in comparison to ICEVs.

Cost

While gasoline powered cars typically average 10 to 50 mpg (5-23 L/100 km), electric cars can average the equivalent of 200 mpg (1.5 L/100 km) with a typical cost of two to four cents per mile. In contrast, gasoline-powered ICEVs currently cost about four to six times as much. The total cost of ownership for modern EVs depends primarily on the cost of the batteries (see below), the type and capacity of which determine several factors such as travel range, top speed, battery lifetime and recharging time; several trade-offs exist. The cost of batteries is primarily a life-cycle cost, which is highly dependent upon both the initial cost, longevity of both the battery and the vehicle, and the battery, charger, motor, and motor power regulator energy-throughput efficiency.

Batteries are usually the most expensive component of electric cars, though the price per kilowatt-hour of charge has fallen rapidly in recent years for the more recently introduced technologies such as lithium-ion and lithium-polymer. Older technologies such as lead-acid have become more expensive due to increase in materials cost, particularly lead, driven by demand for use in powered bicycles (particularly in China and India) and in uninterruptible power supplies to support small computer systems. Increasing returns to scale should lower their cost when electric cars are manufactured on the scale of the current ICE vehicles. Since the late 1990s, advances in battery technologies have been driven by skyrocketing demand for laptop computers and mobile phones, with consumer demand for more features, larger, brighter displays, and longer battery time driving research and development in the field. The electric vehicle marketplace has reaped the benefits of these advances.

Some batteries can be leased or rented instead of bought (see Think Nordic). In 1947, in Nissan's first electric car, the batteries were removable so that they could be replaced at filling stations with fully charged ones.

Ownership costs

In the UK ownership costs include vehicle excise duty or road tax. Electric vehicles are now exempt and so electric car owners will save around £100 per year compared with an average conventional car. There remains some uncertainty about annual depreciation rates and resale values for EVs due to the unknown length of battery-life and the low demand for battery electrics compared to other green car types. As EVs lose their value faster than conventional cars depreciation rates are likely to be higher than for a conventional car at this time.

In the UK, electric car users who install additional recharging equipment will face additional financial penalties. Costs per standard charge point are around £500-£2000, depending on the difficulty of installation. Fully installed fast-chargers will cost between £10,000 and £30,000 per point although this depends on whether an on-board or off-board fast-charging system is used.

Running costs

Some running costs are significantly less for electric cars than for ICE powered cars. In particular, fuel costs are very low due to the competitive price of electricity - fuel duty is zero-rated - and to the high efficiency of the vehicles themselves. Taking into account the high fuel economy of battery electric cars, the fuel costs can be as low as 1.0-2.5p per mile (depending on the tariff). For a typical 10,000 miles per year, switching from a conventional car to an electric car could save around £800 in fuel costs. However if the battery hire is considered a running cost, then the saving on fuel is canceled out by the monthly battery leasing cost.

Electric car operating costs can be directly compared to the equivalent operating costs of a gasoline-powered vehicle. A gallon of gasoline contains about 36.4 kW·h of energy. To calculate the cost of the electrical equivalent of a gallon of gasoline, multiply the utility cost per kW·h by 36.4. Because automotive internal combustion engines are only about 20% efficient, then at most 20% of the total energy in that gallon of gasoline is ever put to use . An electric car's efficiency is affected by its charging and discharging efficiencies. A Typical charging cycle is about 85% efficient, and the discharge cycle converting electricity into mechanical power is about 95% efficient, resulting in 81% of each kW·h is put to use. The electricity generating system in most countries is typically up to 40% efficient, twice as efficient as the conversion in an ICE.

A car powered by an internal combustion engine at 20% efficiency, getting 30 mpg, will require 0.24 Kw·h per mile. At a cost of $3.50 per gallon this is $0.12 per mile. A battery electric version of that same car with a charge/discharge efficiency of 81%, and charged at a cost of $0.10 for kW·h would cost $0.03 per mile, or would be paying the equivalent of $0.88 per gallon.

Energy efficiency and carbon dioxide emissions

Production and conversion electric cars typically use 0.17 to 0.37 kilowatt-hours per mile (0.1–0.23 kW·h/km). Approximately 20% of this power consumption is due to inefficiencies in charging the batteries. Tesla Motors indicates that the well to wheels power consumption of their li-ion powered vehicle is 0.215 kW·h/mi. The US fleet average of 23 miles per gallon of gasoline is equivalent to 1.58 kW·h/mi and the 70 mpg (U.S.) Honda Insight uses 0.52 kW·h/mi (assuming 36.4 kW·h per US gallon of gasoline), so hybrid electric vehicles are relatively energy efficient, and battery electric vehicles are much more energy efficient. A 2001 DOE estimate calculates a battery powered EV at 7¢/kW·h can be driven 43 miles (69 km) for a dollar and at $1.25/gal a gasoline vehicle will go 18 miles (29 km).

Sources of electricity in the U.S. 2006[1]

Generating electricity and providing liquid fuels for vehicles are different categories of the energy economy, with different inefficiencies and environmental harms. A 55% to 99.9% improvement in CO₂ emissions takes place when driving an EV over an ICE (gasoline, diesel) vehicle depending on the source of electricity. Comparing CO₂ emissions can be done by using the US national average of 1.28 lb (0.58 kg) CO₂/(kW·h) for electricity generation, giving a range for BEVs from zero up to 0.2 to 0.5 lb (0.23 kg) CO₂/mi (0.06 to 0.13 kg/km). Because 1 gal of gasoline produces 19 lb (8.6 kg) CO₂ when burned in a typical automobile engine, the average US fleet produces 0.83 lb/mi (0.23 kg/km), a 40 mpg car produces approximately 0.47 lb/mi and the Insight 0.27 lb/mi (0.08 kg/km). CO₂ and other greenhouse gases emissions are minimal for BEVs powered from sustainable electricity sources (e.g. solar energy), but are constant per gallon (or litre) for gasoline vehicles.

Model	Short tons CO2 (conventional, mostly fossil fuel electricity production)	Short tons CO2 (renewable electricity production, e.g., solar panel, or wind power)
2002 Toyota RAV4-EV (pure BEV)	3.8	0.0
2000 Toyota RAV4 2wd (gasoline)	7.2	7.2
Other battery electric vehicle(s)
2000 Nissan Altra EV	3.5	0.0
Hybrid vehicles
2001 Honda Insight	3.1	3.1
2005 Toyota Prius	3.5	3.5
2005 Ford Escape H 2x	5.8	5.8
2005 Ford Escape H 4x	6.2	6.2
Internal combustion engine vehicles
2005 Dodge Neon 2.0L	6.0	6.0
2005 Ford Escape 4x	8.0	8.0
2005 GMC Envoy XUV 4x	11.7	11.7
Table assumes driving 15,000(?) miles per year and is for one year

Aerodynamic drag has a large impact on energy efficiency as the speed of the vehicle increases. See Automobile drag coefficients for a list of cars.

Maintenance

EVs, particularly those using AC or brushless DC motors, have far fewer parts to wear out. An ICE vehicle on the other hand will have many mechanical, fluid, and electrical parts that may include some of the following: pistons, connecting rods, crankshafts, cylinder walls, valves, valve springs, valve guides, camshafts, cambelts, lifters, pushrods, rocker arms, oil pumps, fuel pumps, water pumps, radiators, gearbox (rarely used in EV's), clutch, distributors, spark plugs, air filters, oil filters, coolant and vacuum hoses, injectors, carburettors, turbos, superchargers, gaskets, seals and bearings. All of these parts may wear out over time.

Both hybrids and EVs can use regenerative braking, which greatly reduces wear and tear on friction brakes - Prius taxi drivers report far less frequent brake maintenance.

Acceleration performance

Although some electric vehicles have very small motors, 20 hp (15 kW) or less and therefore have modest acceleration, the relatively constant torque of an electric motor even at very low speeds tends to increase the acceleration performance of an electric vehicle for the same rated motor power. Another early solution was American Motors’ experimental Amitron piggyback system of batteries with one type designed for sustained speeds while a different set boosted acceleration when needed.

Electric vehicles can also utilize a direct motor-to-wheel configuration which increases the amount of available power. Having multiple motors connected directly to the wheels allows for each of the wheels to be used for both propulsion and as braking systems, thereby increasing traction. In some cases, the motor can be housed directly in the wheel, such as in the Whispering Wheel design, which lowers the vehicle's center of gravity and reduces the number of moving parts. When not fitted with an axle, differential, or transmission, electric vehicles have less drivetrain rotational inertia.

A gearless or single gear design in some EVs eliminates the need for gear shifting, giving such vehicles both smoother acceleration and smoother braking. Because the torque of an electric motor is a function of current, not rotational speed, electric vehicles have a high torque over a larger range of speeds during acceleration, as compared to an internal combustion engine. As there is no delay in developing torque in an EV, EV drivers report generally high satisfaction with acceleration.

For example, the Venturi Fetish delivers supercar acceleration despite a relatively modest 300 horsepower (220 kW), and a top speed of around 100 miles per hour. Some DC motor-equipped drag racer EVs, have simple two-speed transmissions to improve top speed. The Tesla Roadster prototype can reach 60 mph (97 km/h) in 4 seconds with a motor rated at 248 hp (185 kW). The Ronaele 300E Mustang is another performance car that has recently emerged, the pure electric can reach 60 mph (97 km/h) in under 4 seconds with a motor rated at 300 horsepower (220 kW).

Batteries

Prototypes of 75 watt-hour/kilogram lithium ion polymer battery. Newer Li-ion cells can provide up to 130 Wh/kg and last through thousands of charging cycles.

Main article: Rechargeable batteries

Rechargeable batteries used in electric vehicles include lead-acid ("flooded" and VRLA), NiCd, nickel metal hydride, lithium ion, Li-ion polymer, and, less commonly, zinc-air and molten salt batteries. The amount of electricity stored in batteries is measured in ampere hours or in coulombs, with the total energy often measured in watt hours.

Charging

Batteries in BEVs must be periodically recharged (see also Replacing, below). BEVs most commonly charge from the power grid (at home or using a street or shop recharging point), which is in turn generated from a variety of domestic resources; such as coal, hydroelectricity, nuclear and others. Home power such as roof top photovoltaic solar cell panels, microhydro or wind may also be used and are promoted because of concerns regarding global warming.

Charging time is limited primarily by the capacity of the grid connection. A normal household outlet is between 1.5 kilowatts (in the US, Canada, Japan, and other countries with 110 volt supply) to 3 kilowatts (in countries with 240 V supply). The main connection to a house might be able to sustain 10 kilowatts, and special wiring can be installed to use this. At this higher power level charging even a small, 7 kilowatt-hour (14–28 mi) pack, would probably require one hour. This is small compared to the effective power delivery rate of an average petrol pump, about 5,000 kilowatts. Even if the supply power can be increased, most batteries do not accept charge at greater than their charge rate ("1C"), because high charge rate has adverse effect on the discharge capacities of batteries.

In 1995, some charging stations charged BEVs in one hour. In November 1997, Ford purchased a fast-charge system produced by AeroVironment called "PosiCharge" for testing its fleets of Ranger EVs, which charged their lead-acid batteries in between six and fifteen minutes. In February 1998, General Motors announced a version of its "Magne Charge" system which could recharge NiMH batteries in about ten minutes, providing a range of sixty to one hundred miles.

In 2005, handheld device battery designs by Toshiba were claimed to be able to accept an 80% charge in as little as 60 seconds. Scaling this specific power characteristic up to the same 7 kilowatt-hour EV pack would result in the need for a peak of 340 kilowatts of power from some source for those 60 seconds. It is not clear that such batteries will work directly in BEVs as heat build-up may make them unsafe.

In 2007, Altairnano's NanoSafe batteries are rechargeable in several minutes, versus hours required for other rechargeable batteries. A NanoSafe cell can be charged to around 95% charge capacity in approximately 10 minutes.

Most people do not always require fast recharging because they have enough time, 30 minutes to six hours (depending on discharge level) during the work day or overnight to recharge. As the charging does not require attention it takes a few seconds for an owner to plug in and unplug their vehicle much like a cell phone. Many BEV drivers prefer recharging at home, avoiding the inconvenience of visiting a fuel station. Some workplaces provide special parking bays for electric vehicles with chargers provided - sometimes powered by solar panels. In colder areas such as Minnesota and Canada there already exists some infrastructure for public power outlets, in parking garages and at parking meters, provided primarily for engine pre-heating.

Connectors

The charging power can be connected to the car in two ways (electric coupling). The first is a direct electrical connection known as conductive coupling. This might be as simple as a mains lead into a weatherproof socket through special high capacity cables with connectors to protect the user from high voltages. The second approach is known as inductive charging. A special 'paddle' is inserted into a slot on the car. The paddle is one winding of a transformer, while the other is built into the car. When the paddle is inserted it completes a magnetic circuit which provides power to the battery pack. In one inductive charging system[7], one winding is attached to the underside of the car, and the other stays on the floor of the garage.

The major advantage of the inductive approach is that there is no possibility of electric shock as there are no exposed conductors, although interlocks, special connectors and ground fault detectors can make conductive coupling nearly as safe. Inductive charging can also reduce vehicle weight, by moving more charging components offboard. Conductive coupling equipment is lower in cost and much more efficient due to a vastly lower component count. An inductive charging proponent from Toyota contended in 1998 that overall cost differences were minimal, while a conductive charging proponent from Ford contended that conductive charging was more cost efficient.

Travel range before recharging and trailers

The General Motors EV1 had a range of 75 to 150 miles (240 km) with NiMH batteries in 1999.

The range of a BEV depends on the number and type of batteries used, and the performance demands of the driver. The weight and type of vehicle also have an impact just as they do on the mileage of traditional vehicles. Electric vehicle conversions depends on the battery type:

• Lead-acid batteries are the most available and inexpensive. Such conversions generally have a range of 30 to 80 km (20 to 50 mi). Production EVs with lead-acid batteries are capable of up to 130 km (80 mi) per charge.

• NiMH batteries have higher energy density and may deliver up to 200 km (120 mi) of range.

• New lithium-ion battery-equipped EVs provide 400–500 km (250–300 mi) of range per charge. Lithium is also less expensive than nickel.

Finding the economic balance of range versus performance, battery capacity versus weight, and battery type versus cost challenges every EV manufacturer.

With an AC system regenerative braking can extend range by up to 50% under extreme traffic conditions without complete stopping. Otherwise, the range is extended by about 10 to 15% in city driving, and only negligibly in highway driving, depending upon terrain.

BEVs (including buses and trucks) can also use genset trailers and pusher trailers in order to extended their range when desired without the additional weight during normal short range use. Discharged battery set trailers can be replaced by recharged ones along a route. If rented then maintenance costs can be deferred to the agency.

Such BEVs can become Hybrid vehicles depending on the trailer and car types of energy and powertrain.

Replacing

An alternative to recharging is to exchange drained or nearly drained batteries (or battery range extender modules) with fully charged batteries.

Re-filling

Zinc-bromine flow batteries or Vanadium redox batteries can be re-filled, instead of recharged, saving time. The depleted electrolyte can be recharged at the point of exchange, or taken away to a remote station.

V2G: uploading and grid buffering

Main article: Vehicle-to-grid

Smart grid allows BEVs to provide power to the grid in anytime, specially:

• During peak load periods, when the selling price of electricity can be very high. These vehicles can then be recharged during off-peak hours at cheaper rates while helping to absorb excess night time generation. Here the vehicles serve as a distributed battery storage system to buffer power.

• During blackouts, as backup.

Lifespan

Individual batteries are usually arranged into large battery packs of various voltage and ampere-hour capacity products to give the required energy capacity. Battery life should be considered when calculating the extended cost of ownership, as all batteries eventually wear out and must be replaced. The rate at which they expire depends on a number of factors.

The depth of discharge (DOD) is the recommended proportion of the total available energy storage for which that battery will achieve its rated cycles. Deep cycle lead-acid batteries generally should not be discharged below 80% capacity. More modern formulations can survive deeper cycles.

In real world use, some fleet Toyota RAV4 EVs, using NiMH batteries, will exceed 100,000 miles (160,000 km), and have had little degradation in their daily range. Quoting that report's concluding assessment:

The five-vehicle test is demonstrating the long-term durability of Nickel Metal Hydride batteries and electric drive trains. Only slight performance degradation has been observed to-date on four out of five vehicles.... EVTC test data provide strong evidence that all five vehicles will exceed the 100,000-mile (160,000 km) mark. SCE’s positive experience points to the very strong likelihood of a 130,000 to 150,000-mile (240,000 km) Nickel Metal Hydride battery and drive-train operational life. EVs can therefore match or exceed the lifecycle miles of comparable internal combustion engine vehicles. In June 2003 the 320 RAV4 EVs of the SCE fleet were used primarily by meter readers, service managers, field representatives, service planners and mail handlers, and for security patrols and carpools. In five years of operation, the RAV4 EV fleet had logged more than 6.9 million miles, eliminating about 830 tons of air pollutants, and preventing more than 3,700 tons of tailpipe carbon dioxide emissions. Given the successful operation of its EVs to-date, SCE plans to continue using them well after they all log 100,000-miles.

Jay Leno's 1909 Baker Electric (see Baker Motor Vehicle) still operates on its original Edison cells. Battery replacement costs of BEVs may be partially or fully offset by the lack of regular maintenance such as oil and filter changes required for ICEVs, and by the greater reliability of BEVs due to their fewer moving parts. They also do away with many other parts that normally require servicing and maintenance in a regular car, such as on the gearbox, cooling system, and engine tuning. And by the time batteries do finally need definitive replacement, they can be replaced with later generation ones which may offer better performance characteristics, in the same way one might replace an old laptop battery.

Safety

The safety issues of battery electric vehicles are largely dealt with by the international standard ISO 6469. This document is divided in three parts dealing with specific issues:

• On-board electrical energy storage, i.e. the battery
• Functional safety means and protection against failures
• Protection of persons against electrical hazards.

Firefighters and rescue personnel receive special training to deal with the higher voltages and chemicals encountered in electric and hybrid electric vehicle accidents. While BEV accidents may present unusual problems, such as fires and fumes resulting from rapid battery discharge, there is apparently no available information regarding whether they are inherently more or less dangerous than gasoline or diesel internal combustion vehicles which carry flammable fuels.

Future

The future of battery electric vehicles depends primarily upon the cost and availability of batteries with high energy densities, power density, and long life, as all other aspects such as motors, motor controllers, and chargers are fairly mature and cost-competitive with internal combustion engine components. Li-ion, Li-poly and zinc-air batteries have demonstrated energy densities high enough to deliver range and recharge times comparable to conventional vehicles.

Bolloré a French automotive parts group developed a concept car the "Bluecar" using Lithium metal polymer batteries developed by a subsidiary Batscap. It had a range of 250 km and top speed of 125 km/h.(Bluecar) document

Firefly Energy has developed a carbon foam-based lead acid battery with a reported capacity from 90-160 Watt-hours/kg

The cathodes of early 2007 lithium-ion batteries are made from lithium-cobalt metal oxide. That material is expensive, and can release oxygen if its cell is overcharged. If the cobalt is replaced with iron phosphates, the cells will not burn or release oxygen under any charge. The price premium for early 2007 hybrids is about US $5000, some $3000 of which is for their NiMH battery packs. At early 2007 gasoline and electricity prices, that would break even after six to ten years of operation. The hybrid premium could fall to $2000 in five years, with $1200 or more of that being cost of lithium-ion batteries, providing a three-year payback.

Experimental supercapacitors and flywheel energy storage devices offering comparable storage capacity, higher charging rates, and lower volatility have the potential to overtake batteries as the prominent rechargeable storage for EVs. The FIA has included their use in its sporting regulations of energy systems for Formula One race vehicles in 2007 and 2009, respectively. EEStor claims to have developed a supercapacitor for electricity storage. These units use barium titanate coated with aluminum oxide and glass to achieve a level of capacitance claimed to be much higher than what is currently available in the market. The claimed energy density is 1.0 MJ/kg (existing commercial supercapacitors typically have an energy density of around 0.01 MJ/kg, while lithium ion batteries have an energy density of around 0.54–0.72 MJ/kg). EEStor claims a less than 5 minute charge should give the supercapacitor sufficient energy to drive a car 250 miles (400 km).

Hobbyists, conversions, and racing

Eliica prototype

Hobbyists often build their own EVs by converting existing production cars to run solely on electricity. There is a cottage industry supporting the conversion and construction of BEVs by hobbyists. Universities such as the University of California, Irvine even build their own custom electric or hybrid-electric cars from scratch.

Short-range battery electric vehicles offer the hobbyist comfort, utility, and quickness, sacrificing only range. Short-range EVs may be built using high-performance lead–acid batteries, using about half the mass needed for a 60 to 80 mile (100 to 130 km) range; the result is a vehicle with about a thirty mile (50 km) range, which 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, but are expensive due to the higher cost for these higher-performance batteries. By including a manual transmission, short-range EVs can obtain both better performance and greater efficiency than the single-speed EVs developed by major manufactures. Unlike the converted golf carts used for neighborhood electric vehicles, short-range EVs may be operated on typical suburban throughways (40 to 45 mph (72 km/h) or 60 or 70 km/h speed limits are typical) and can keep up with traffic typical on such roads and the short "slow-lane" on-and-off segments of freeways common in suburban areas.

Japanese Professor Hiroshi Shimizu from Faculty of Environmental Information of the Keio University created the limousine of the future: the Eliica (Electric Lithium Ion Car) has eight wheels with electric 55 kilowatt hub motors (8WD) with an output of 470 kilowatts and zero emissions, a top speed of 370 kilometers per hour, and a maximum range of 320 kilometers provided by lithium-ion-batteries (video at eliica.com). However, current models cost approximately $300,000 US, about one third of which is the cost of the batteries.

Alternative green vehicles

Main article: Green vehicle § Types

Other Types of green vehicles include other vehicles that go fully or partly on alternative energy sources than fossil fuel. Another alternative is to use alternative fuel composition in conventional fossil fuel-based vehicles, making them go partly on renewable energy sources.

Other approaches include personal rapid transit, a public transportation concept that offers automated on-demand non-stop transportation, on a network of specially-built guideways.

See also

• Altairnano
• Electric boat
• Electric bus
• Electric motorcycles and scooters
• Electric vehicle conversion
• Compressed air car
• Hybrid vehicle
• List of emerging technologies
• List of production battery electric vehicles
• Miles Electric Vehicles
• Neighborhood electric vehicle
• Phoenix Motorcars
• Plug-in hybrid (PHEV)
• Project Better Place
• Rechargeable battery
• Vehicle-to-grid
• ZAP (motor company)

External links

Patents

• U.S. patent 523,354, E. E. Keller, Electrically Propelled Preambulator
• U.S. patent 594,805, Hiram Stevens Maxim, Motor vehicle
• U.S. patent 772,571, H. S. Maxim, Electric motor vehicle

Organizations

• Open Source Electric Car by Society for Sustainable Mobility
• US Electric Auto Association (EAA) and recharging points

News stories

• GM Engineer discusses battery integration challenge - Jan 30, 2007
• GM does U-turn on electric car program, now says electric cars are the future 7 November 2006
• Renault Nissan to invest in Israeli electric car project 12 January 2007

Electric vehicles

• 'Inevitable Shift' to Electric Cars?