• Declining fuel reserves
• Increasing Demand
• Environmental Degradation
An electric-powered car cannot go more than 100 miles (161 km) between recharging,
is difficult to re-charge and doesn't drive beyond 60 mpg, although it emits little
pollution Hence, Hybrid Vehicles.
• Conventional Car Engine • Fuel Tank
• Electric Motor • Generator
• Batteries • Transmission System
Conventional Car Engine :
• Gasoline Engine ( also Petrol or Diesel respectively )
• Smaller in size
• Greater Efficiency and Lesser Emission
Fuel Tank :
• Stores the fuel needed to run the car engine
Electric Motor and Generator :
• A motor will be needed to take energy from the batteries and accelerate
• Generators are needed to produce the electrical power.
• Stores and releases energy as required by the car
• Energy from the battery is taken by the motor
• Wide acceptance as a recyclable battery from the environmental standpoint
• Examples : Pb-acid, NiMH, and Lithium (Li)-ion batteries
• Long cycle life with maintenance free and high safety mechanisms built into the
Nickel Metal Hydride Battery
• Energy Density of 30-80Wh/kg
• Can have exceptionally long lives if used properly
• Faster charging
• Poor efficiency
• High self-discharge
• Poor performance in cold weather
Lithium Ion Battery
• High energy density
• Solid electrolyte
• Typically 40% smaller and weigh half than NiMH
• Open circuit voltage (OCV) of approximately 3- 4V
at full charge
• Lesser charge discharge time
• More environment friendly
• Overcharging may cause damage to
• Dangerous if not handled carefully
• Safety features required for both cell
and battery pack
Drive Train Structure
Power Split or Series-
• ICE running mostly at optimal speed and
• ICE can be turned off in zero emission zone
• Low floor possible
• Low fuel consumption
• High fuel efficiency
• Many energy conversions owing to loss of
• More suitable for city driving
• ICE directly connected to wheels -> fewer power conversions
• Electric machine and gearboxes present -> ICE working pt. can be
• ICE & electrical machines must be mounted together -> no low
Honda Civic Hybrid
• ICE can be turned off
• ICE speed can be chosen by adjusting generator speed
• Power vicious cycle may occur leading to low efficiency
• Relatively complex
• IC Engines equipped with an electric machine allowing the engine to be turned
off whenever the car is coasting, braking, or stopped, yet restart quickly.
• May employ regenerative brake and some level of power assist to the IC
• More fuel efficient (10-15%) compared to conventional gas powered car
• Less expensive than fully hybrid
• Less fuel efficient than fully hybrid
• Chevrolet Silverado
• Honda Civic
• Rechargeable batteries
• Electric motor -> primary power source,
gasoline engine -> supplemental
• Require deeper battery charging and
discharging cycles than conventional
• Charging topologies
―Using electric motor's inverter and
• Modes of Operation
― Charge-depleting mode
― Charge-sustaining mode
― Mixed mode
• Speed : 104 km/h
• Distance : 160 km
• Weight(empty) : 700 kg
• E - motor : 13 kW ( max.)
• Battery : 72 V ( 14 kWh) Li-ion
• Energy Recuperation
Mahindra Reva NXR
Hybrid-electric vehicles (HEVs) combine the benefits of gasoline engines and electric
motors and can be configured to obtain different objectives, such as improved fuel
economy, increased power, or additional auxiliary power for electronic devices and power
Some of the advanced technologies typically used by hybrids includes :
Regenerative Braking. The electric motor applies resistance to the drivetrain causing the
wheels to slow down. In return, the energy from the wheels turns the motor, which
functions as a generator, converting energy normally wasted during coasting and braking
into electricity, which is stored in a battery until needed by the electric motor.
Electric Motor Drive/Assist. The electric motor provides additional power to assist the
engine in accelerating, passing, or hill climbing. This allows a smaller, more efficient engine
to be used. In some vehicles, the motor alone provides power for low-speed driving
conditions where internal combustion engines are least efficient.
Automatic Start/Shutoff. Automatically shuts off the engine when the vehicle comes to a
stop and restarts it when the accelerator is pressed. This prevents wasted energy from
Regenerative Braking :
•The regenerative braking effect drops off at lower speeds
•Friction Brake required as backup
• Friction based braking required in cases of adverse conditions in two-wheel drive
• It is normal to also incorporate dynamic braking to absorb the excess energy
• Friction braking is required to absorb the surplus energy in order to allow an
acceptable emergency braking performance
Certain Basic Parameters to look out for while buying a Hybrid car :
As told earlier hybrid cars have a much more initial expense than the ordinary ones.
Hybrid cars range in prices from $20,000 to $50,000. The price varies according to the
size of the car and also the style. So, decide wisely as this is a lot of money.
Clearly, hybrids have a lot more mileage than the conventional cars. But still try to buy
cars that have better mileage among the category. There are cars with mileages varying
from 65mpg to 28 mpg.
Travel comfort :
For long distance traveling, travel comfort plays a very important role. There are cars
with comfortable hatchback and others with leg room, boot capacity and overall space.
• Very less pollution.
• Better mileage.
• More reliable and comfortable.
• Very clean cars due to less emissions.
• Batteries need not be charged by an external source.
• Warranties available for batteries as well as motors.
• Less dependence on fuels.
• The initial cost will be very high – higher than other cars.
• Since a lot of batteries will be needed, the car will be very heavy.
• As there are electrical components, there is risk of shock during an accident.
• The vehicle can be repaired only by professionals.
• Spare parts will be very costly and rare.
• Toyota continues to build momentum as a leader of the hybrid industry.
• Next generation of hybrids will feature improved batteries with higher density.
•The next-generation Prius, specifically, will combine our advance battery technologies
with new electric motors that are smaller in size, and feature improved power density
• While the adoption rate for hybrids in the US is small today (2.2% of new car sales in
2011),] this compares with a 17.1% share of new car sales in Japan in 2011, and it has
to potential to be very large over time as more models are offered and incremental
costs decline due to learning and scale benefits
• These analogs collectively suggest it would take at least 30 years for hybrid and
electric vehicles to capture 80% of the US passenger vehicle stock.
• Don't get us wrong, save the trees and the environment, but we still prefer our
burners any day of the week.