Battery Electric Cars

Battery electric cars The beginning of a new era Presented by, Biswajit Saha 0401212431 Electrical engg.

History 1. Between 1832 and 1839 Scottish businessman Robert Anderson invented the first crude electric carriage. 2. 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.

3.BEVs, produced in the USA by AnthonyElectric,Baker,Detroit,Edison,Studebae r,and others during the early 20th Century for a time out-sold gasoline-powered vehicles.The top speed of these early electric vehicles was limited to about 32 km/h (20 mph).Electrics did not require hand-cranking to start.

4. 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. 5. The 1947 invention of the point-contact transistor marked the beginning of a new era for BEV technology.Within a decade, Henney Coachworks had joined forces with National Union Electric Company to produce the first modern electric car based on transistor technology.

Comparision to internal combustible vehicle 1.

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

2.

While it is a dream of ICEVs to reach 75 or 100 mpg (3L/100 km), electric vehicles naturally reach the equivalent of 200 mpg (1.5 L/100km) with their typical cost of two to four cents per mile. The total cost of ownership for modern BEVs depends primarily on the batteries that is less than ICEVs when compared to refuelling cost.

3.Ownership costs for BEVsare higher than

ICEVequivalents, primarily because their purchase price is higher to begin with. 4. 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 BEVs, the fuel costs can be as low as 1.0-2.5p per mile (depending on the tariff).

Dynasty EV 4(a Canadian BEV)

Energy efficiency and carbon dioxide emissions

Production and conversion BEVs typically use 0.17 to 0.37 kilowatt-hours per mile (0.1– 0.23 kWh/km).Nearly half 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 kwh per mile. The US fleet average of 23 miles per gallon of gasoline is equivalent to 1.58 kWh per mile and the 70 MPG Honda Insight uses 0.52 kWh per mile,so hybrid electric vehicles are relatively energy efficient and battery electric vehicles are much more energy efficient.

Sources of electricity in the U.S. 2005

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 lbs CO2/kWh for electricity generation, giving a range for BEVs from zero up to 0.2 to 0.5 lbs CO2/mi (0.06 kg/km to 0.13 kg/km). Since 1 gal of gasoline produces 19 lbs CO2 the average US fleet produces 0.83 lbs/mi (0.23 kg/km) and the Insight 0.27 lbs/mi (0.08 kg/km).CO2 and other greenhouse gases emissions do not exist for BEVs powered from sustainable electricity sources (e.g. solar energy), but are constant per gallon (or litre) for gasoline vehicles

Table showing Carbon emmisions MODEL

Carbon emissions Carbon emissions for conventional for elec. production Renewable elec. production

Toyota RAV4-EV (BEV)

3.8

3.1

Toyota RAV4 2wd (ICE)

7.2

7.2

Nissan Altra EV(BEV)

3.5

0.0

HYBRID VEHICLES

MODEL

Carbon emissions Carbon emissions for conventional for elec. production Renewable elec. production

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

Maintenance and performance Maintenance 1.

2.

Venturi Fetish - a limited production electric car capable of reaching 0 to100 km/hr in 4.5 seconds

EVs, particularly those using AC or brushless DC motors, have far fewer mechanical parts to wear out. An ICEV on the other hand will have pistons, valves, camshafts, cambelts, gearbox and a clutch, all of which can wear out. Both hybrids and EV's use regenerative braking, which greatly reduces wear and tear on friction brakes

Performance 1.

Eliica prototype

Although some electric vehicles have very small motors, 20 hp 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 ratedmotor power.

2. 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. 3. When not fitted with an axle, differential, or transmission, electric vehicles have less drivetrain rotational inertia. 4. A gearless or single gear design in some BEVs eliminates the need for gear shifting, giving such vehicles both smoother acceleration and smoother braking. 5. 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. So it can be truly said these are high perforfance BEVs that can give ICEVs(supercars) run for their money.

Charging 1. 2. 3.

4. 5.

Batteries in BEVs must be periodically recharged . BEVs most commonly charge from the power grid(at home or using a street or shop recharging point).Home power such as roof top photovoltaic solar cell panels, microhydro or wind may also be used . Charging time is limited primarily by the capacity of the grid connection. Even if the supply power can be increased, most batteries do not accept charge at greater than their charge rate ("C1".). In 1995, some charging stations charged BEVs in one hour. In November 1997, Ford purchased a fast-charge system produced by AeroVironment called "PosiCharge" 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. In 2007, Altairnano's NanoSafe batteries are rechargeable in a few minutes, versus hours required for other rechargeable batteries. A NanoSafe cell can be charged to over 80% charge capacity in about one minute.

Connectors

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

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 coupling. 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.

Batteries used Rechargeable batteries used in electric vehicles include leadacid ("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 kWh.

75 watt-hour/kilogram lithium polymer battery prototypes

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• • •

The Toyota RAV4 EV was powered by twenty-four 12 volt batteries, with an operational cost equivalent of over 165 15 miles per gallon at

Lead-acid batteries are the most available and inexpensive. Such conversions generally have a range of 30 to 80 km (20 to 50 miles). Production EVs with lead-acid batteries are capable of up to 130 km (80 miles) per charge. NiMH batteries have higher energy density and may deliver up to 200 km (120 miles) of range. New lithium-ion battery -equipped EVs provide 400-500 km (250-300 miles) of range per charge.[19] Lithium is also less expensive than nickel. An alternative to recharging is to exchange drained or nearly drained batteries (or battery range extender modules) with fully charged batteries.

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. 2. Functional safety means and protection against failures. 3. Protection of persons against electrical hazards 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 of BEVs 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 automative 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"The cathodes of early 2007 lithium-ion batteries are made from lithium-cobalt metal oxide. This material is pricey, 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

Disadvantages of BEVs • Electricity is produced using such methods as nuclear fission, with its attendant regulatory and waste issues, or (more often) by burning coal, the latter producing about 0.97 kg of CO2 (2.1 pounds) per kilowatt-hour plus other pollutants and strip-mining damages: electric vehicles are therefore not "zero emissions" in any real-world sense, except at their point of use unless renewable energy(solar, wind, wave, tidal, geothermal, or hydro power) is employed; Zero emission electrical sources such as solar panels must still be manufactured, producing various pollutants. • Limited driving range available between recharging (using certain battery technologies) • Expensive batteries, which may cost US$2,000 (lead acid) to $20,000 (li-ion) to replace; Poor cold weather performance of some kinds of batteries. • Danger of electrocution and electromagnetic interference. • Poor availability of public charging stations reduces practicality and may hinder initial take-up. People who live in flats or houses without private parking may not have an option to charge the vehicle at home

Some BEV vintage cars

Camille Jenatzy in electric car La Jamais Contente, 1899

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