Download Battery electric cars

Battery electric
cars
The beginning of a new era
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,Stu
debaer,and others during the early 20th
Century for a time out-sold gasolinepowered 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.
2.
Tzero an older model
electric vehicle on a
drag race with a Dodge
Viper left behind
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
Dynasty EV 4(a Canadian
BEV)
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 zerorated - 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 1.02.5p per mile (depending on
the tariff).
Energy efficiency and carbon dioxide
emissions
Sources of electricity in
the U.S. 2005
Production and conversion BEVs
typically use 0.17 to 0.37 kilowatthours 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.
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
for conventional
elec. production
Carbon emissions
for
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
for conventional
elec. production
Carbon emissions
for
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
•
•
•
The Toyota RAV4 EV was
powered by twenty-four 12
volt batteries, with an
operational cost equivalent
of over 165 miles per gallon
at
15 2005 US gasoline prices
•
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 threeyear 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 kilowatthour 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 )