Advantages and Disadvantages of Battery Electric Vehicle

Air pollution -EVs do not produce any tailpipe emissions. They are cleaner than conventional vehicles, even when power-plant emissions are included. If battery recharges using renewable energy sources like wind, solar, or hydropower, they cause no air pollution at all.

Global-warming pollution - As with air pollution, electric power plants are the only source of global-warming pollutants from EVs. When EVs recharge using renewable energy sources, they do not cause any global warming emissions at all. Even if EVs are recharged using fossil fuels, they can cut global warming emissions reasonably.

Costs - EVs cost significantly more than gasoline vehicle, mostly because the battery packs. Higher vehicle prices are partially offset by the fact that fuel costs for battery electrics are about one-third those of a gasoline-powered vehicle. And because EVs have fewer moving parts than gasoline cars, they require less maintenance.

Performance - To the driver, EVs offers a quiet, smooth, and high-performance driving experience. The first-generation EVs had a real-world driving range of 50 to 80 miles. Battery advances now permit EVs to travel over a 100 miles on a charge, with future increases still possible.

Battery Electric Vehicles - Some models

Mahindra Reva Electric Vehicles Private Limited, formerly known as the REVA Electric Car Company (RECC), is an Indian company based in Bangalore, designing and manufacturing electric vehicles. The REVA Electric Car Company was a joint venture between Maini Group of India and AEV LLC of California and venture backed by lead US investors Global Environment Fund and Draper Fischer Jurvetson. It is manufacturing the very popular electric vehicle REVA. It is an urban electric micro-car seating two adults and two children. RECC currently produces two versions of the REVA one is REVAi equipped with lead-acid batteries, which has a nominal range of 80 km (50 mi) per charge and a top speed of 80 km/h (50 mph). Another model is REVA L-ion, equipped with Lithium-ion batteries, which has range of 120 km (75 mi) per charge. The REVA has been sold in India since 2001 and in the UK since 2003. RECC also built REVA-NXR & REVA-NXG electric cars. The production of NXR is expected in 2011 and of NXG in 2012. NXR has a top speed of 104 km/h (65 mph) and a range of 160 km (99 mi) and NXG has range of 200 km (124 mi) per charge and a top speed of 120 km/h (75 mph). RECC has constructed a 30,000 capacity assembly plant in Bangalore. It is currently the world's largest operational plant specially dedicated to the assembly of battery electric vehicles. 

Nisan is working on electric car named as Nissan Leaf (Leading Environmentally Friendly Affordable Family Car). Limited sale of its will start in 2010-11 but its full production is expected in 2012.Its expected all-electric range is 100 miles (160 km) on the EPA city driving cycle. The Leaf uses an 80 kW (110 hp) 280 N-m (210 lb-fts) synchronous motor which is powered by a 24 kilowatt-hours (86 MJ) lithium ion battery pack rated to deliver power up to 90 kW (120 hp). It is having an on-board 3.3 kW charger and 7.5 m (25 ft) cable. Leaf can be fully recharged from empty in less than 20 hours from a standard household outlet (120 volt, 15 amps). It can be charged in 8 hours from a 220/240 volt 30 amp supply. Using quick charging it can be charged to 80% capacity in about 30 minutes, Nissan has developed its own 500 V quick charger. It can go upto the speed of 90 mph. It is also having feature of regenerative braking.

In June 2009 BMW began field testing in the U.S. of its all-electric car Mini E through the leasing of 500 cars to private users. Another field test was launched in the U.K. in December 2009, where more than forty Mini E cars were handed to private users for a two consecutive six-month field trial periods. Field testing in Paris is scheduled to begin in 2010. A total of 100 trial vehicles were assigned to Germany for field testing, which is scheduled to begin in Munich in September 2010. Field testing in Beijing is scheduled to begin in 2010. This car is driven by a synchronous electric motor of 150 kW (204 hp) 220 N-m (160 lb-ft). The Mini E employs a lithium-ion battery pack with an overall capacity of a 35 kilowatt-hours (130 MJ). The car’s range is 156 miles (251 km) on a single charge under optimal conditions. Top speed is electronically limited to 95 mph (153 km/h). Estimates of normal driving conditions put ranges at 109 miles (175 km) city and 96 miles (154 km) highway. The Mini E can be charged through 120-volt 12 amp supply in approximately 26.5 hours. It can be charged with 240-volt 32amp supply in approximately 4.5 hours or in 3 hours with 240 volt 48 amp supply.

Renault is working on an electric car Renault Fluence Z.E., it is expected to launch in 2011. It is fitted with a 22 kWh lithium-ion battery which allows a total all-electric range of 160 km (99 mi) according to Renault, with speeds up to 135 km/h (84 mph). Battery can be charged by 16 A 220 V house hold supply in 6-8 hours or at fast charging station by using 32A 400V supply in approximately 30 mins. It is having synchronous electric motor of peak power 70 kW (94 hp) at 11,000 rpm and maximum torque of 226 N-m. 

The Tesla Model S is an electric car developed by Tesla Motors. The prototype vehicle was displayed on March 26, 2009. Production for the retail market is expected to begin in early 2012. The base model will have a range of 160 miles (260 km) with a 42 kW·h Lithium ion battery pack when fully charged, and a 0 to 60 mph (0 to 97 km/h) acceleration of 5.6 seconds. There will also be larger battery packs available of 65 kW·h & 85 kW·h with ranges of 230 and 300 miles (370 and 480 km). Normal charging times will be 3 to 5 hours, depending on the battery capacity and a 45-minute Quick Charge will be possible when connected to a 480 V outlet.  Top speed will be 195 kmph.

The Mitsubishi i MiEV (Mitsubishi innovative Electric Vehicle) is an electric car launched for sales in Japan in April 2010 and in Hong Kong in May 2010. Sale of i MiEV in UK and USA is expected in 2011. The car has a range of 130 kilometres (80 mi) for the 16 kW·h lithium-ion pack and 160 kilometres (100 mi) for the 20 kW·h pack with Japanese 10-15 mode driving pattern. Top speed is 130 kilometres per hour (80 mph). It is having permanent magnet synchronous motor of 47 kW 180 N-m. It can be fully charged with on board charger by house hold supply of 200v 15 A in 7 hours and with 100V 15 A in 15 hours. This can also be quickly charged for 80% charging level by quick charging system of 3-phase 200v-50KW supply in 30 minutes only.

Basic Principle of Battery Electric Vehicles (BEV)

Battery Electric Vehicles use the energy stored in batteries for vehicle propulsion. The gasoline engine is replaced by an electric motor. The electric motor gets its power through a controller from rechargeable batteries. The heart of an electric car is the combination of electric motor, controller, and batteries. The accelerator pedal hooks to a pair of potentiometers (variable resistors), and these potentiometers provide the signal that tells the controller how much power it is supposed to deliver. The controller can deliver zero power (when the car is stopped), full power (when the driver floors the accelerator pedal), or any power level in between. There are mainly two kinds of arrangements namely DC Motor-Controller and AC Motor-Controller. In DC Motor-Controller arrangement a simple DC controller connected to the batteries and the DC motor.  The controller takes DC power from batteries and delivers it to the motor in a controlled way (Fig.1a). In AC Motor-Controller arrangement a simple AC controller connected to the batteries and the AC motor.  This controller converts DC supply from batteries to AC supply for AC motor. In addition controller provides a charging system for the batteries and a DC-to-DC converter to recharge the 12-volt accessory battery (Fig.1b).

Introduction of Electric Vehicles

Environmental as well as economical issues provide a compelling stimulus to develop clean, efficient, and sustainable vehicles for urban transportation. Automobiles and cars constitute an integral part of our everyday life, but the exhaust emissions of conventional internal combustion engine vehicles are the major source of urban pollution that causes the greenhouse effect that leads to global warming. The dependence on oil as the only source of energy for passenger cars has economical and political implications, and the crisis are becoming inevitably acute as the oil reserve of the world are diminishing very fast. The number of automobiles in the world doubled to about a billion or so in the last 10 years. The increasing number of automobiles being introduced on the road every year is adding tremendous pollution problems. There is also an economic factor inherent in the poor energy conversion efficiency of combustion engines. When efficiency of electric vehicle is evaluated on the basis of conversion from crude oil to traction effort at the wheels, it makes a difference. Emission due to power generation at power plant itself is much easier to regulate than that emanating from IC engine vehicles. The pollution from individual vehicles is scattered. Also, People living in cities are not exposed to power plant related emissions, as these are mostly located outside urban areas. Electric vehicles having high efficiency electric motors, controllers and powered by alternative energy sources provide the means for a clean, efficient, and environment friendly urban transportation system. Electric vehicles have no direct emissions, having the potential to curb the pollution problem in an efficient way. Consequently, Electric Vehicles are the only zero emission vehicles possible.

Electric vehicles as discussed in earlier article paved their way into public use as early as the middle of the 19th century, even before the introduction of gasoline-powered vehicles. In the year 1900, 4200 automobiles were sold, out of which 40% were steam powered, 38% were electric powered, and 22% were gasoline powered. However, the invention of the starter motor, inconvenience in battery charging and improvements in technology of gasoline powered vehicles and their mass production, abundant availability of crude oil led to the disappearance of the Electric Vehicle in the early 1900s. Nobody at that time ever thought of energy crises prevailing in current decade and future. Therefore, Environmental issues and the dependence on oil led to the resurgence of interest in Electric Vehicles back again in the 1960s. Development in the technologies added to environmental and economic concerns over the next several decades, increasing the demand for investing in research and development for Electric Vehicles. Recently major automobile manufacturers planned to reintroduce their own electric or hybrid electric vehicles. The trend increases today, with EVs serving as zero-emission vehicles, and hybrid electric vehicles already filling in for ultralow-emission vehicles.