How To Increase The Range Of Electric Vehicles

Due to the shorter range of the electric vehicles as compared to the conventional ones, the range of the electric vehicles is considered as the major barrier in accepting an electric vehicle. The shorter range effects a number of parameters of the vehicle: design, style, and operational factors. This article will show you how to increase the range of electric vehicles by showing you how operation setting can affect its range.

Comparing Battery Capacity

Battery capacity is the major design factor of an electric vehicle. Both the weight and the price of the vehicle are influenced by the battery size. An electric car's range can be extended by using the right size battery pack. For example, if an electric vehicle has a battery of 24kWh and the daily route of the vehicle does not exceed the 50km, then it is wasteful because a battery having half its capacity could could do the job. By doing this change, the weight of vehicle will decrease causing it to improve the overall efficiency of the vehicle.

In the modern car designs, the customer has the choice to choose the battery of the required size according to its need. The environment plays an important role in the range because a vehicle cannot perform efficiently in the extreme cold and hot temperatures. In the modern techniques, the manufacturers are trying to introduce the cooling and the heating system for the batteries in order to prevent this loss.

Figure 1: Electric SUV

What Can Effect The Range Of A Vehicle?

Tire pressure, which is a technical requirement of all cars, can effect the range of a vehicle. Also, axillary systems like the use of the air conditioning and heater can reduce it. It is necessary for a driver, electric or diesel car, to develop good driving habits to increase the range of the vehicle.

There are various techniques used for this purpose such as regenerative braking, which stores energy lost during braking. Another possibility would be to develop a system that would assist the driver during such modes to help the vehicle's efficiency. 

As discussed, there are a number of factors which can be changed to increase the range of the electric vehicle. Some major factors are:

Battery Sizing

The technical properties of an electric car are directly related to the size of the battery used. The weight and amount of the average energy consumed per day decide the size of the battery, and ultimately the range. By using a large battery size, the range of the electric car increases because it is able to complete more trips with a longer battery life.

As compared to the efficiency of internal combustion engine, the efficiency of the electric motors is high to reduce the operational cost and cause zero emissions. On the other hand, the energy storage capacity of the battery is increased. This causes the cost of the production battery to increase which then increases the customers price.

In conclusion, the selection of the size of the battery used in the vehicle is the tradeoff of the customer between the investment cost of the vehicle and the lifetime running cost of the electric vehicle.

Figure 2: Electric battery system

Shape Impact

The range and power of the electric vehicle is directly affected by the driving resistance acting on the vehicle. The resistance of the air increases quadratically with the speed of the vehicle. This way, the resistance is directly related to the shape of the body. The aerodynamic drag coefficient of the vehicle decreases as we increase the aerodynamics of the vehicle. So, it is a major factor that increases the range.

Power Train

There is no doubt that the electric vehicles are the future of the automotive industry. One of the biggest issue for consumers is the less range and price. Since the solution to increase the range of the vehicle is to use the large batteries, it will then cause the price to raise. There is a need to increase the range of the vehicle without changing the batteries. 

The efficiency of a gasoline car is measured in term of the MPG. Similarly, the energy consumption rate of electric vehicles is measured in kWh/km. As the drive train would be more efficient, the amount of the energy consumed by the electric vehicle would be less. This way, it can cover long distance with the same battery.

There are four main components of an electric powertrain: battery, direct current, electric motor, and DC-DC converter. The batter is used to store electricity. An inverter converts the DC, direct current, into alternating current, AC. Additionally, the electric motor provides the energy to move the vehicle. The DC-DC converter gives the exact voltage to the motor from the battery. This can be shown in the figure below.

Figure 3: Electric basic powertrain

The efficiency of an electric powertrain is defined as the ratio of the energy provided to the battery to the energy output of the motor. If the ratio is 100%, then the whole electrical energy is converted to the mechanical energy and the losses are zero, which is nearly impossible.

In the energy conversion process, a number of losses occurs because the efficiency of the powertrain is not a constant value. For example, the efficiency of the motor and the inverter varies from 60% to 96% depending upon the drive profile the speed and the torque depending upon its position in the drive train. 

Regenerative Braking

Most of the electric vehicles come with the regenerative braking, which slows down the vehicle during braking. Traditional braking is used for heavy conditions, such as heavy traffic, but it causes the energy from the braking system to be wasted. The energy wasted during traditional braking is stored in the form of the electrical energy of the battery.

However, in the normal conditions, the use of the regenerative braking can improve the efficiency of the electric vehicle. In order to improve the efficiency, it is necessary to use the car's maximum regenerative setting as more as possible and don’t press the brake pads too often and hard. It is crucial to maximize regenerative braking to improve range and the car itself.

Figure 4: Regenerative braking system

Speed

According to the laws of physics, the faster you go, the more the amount of the energy you use. It is the case for cars as well, even electric ones. They depend upon the power source used to provide energy. When we accelerate faster, it produces more torque and creates about ten thousands of revolutions per minute than most of the electric vehicles uses a single ration of gearbox. To obtain the energy from the single transmission, the motor has to work harder as you go. The power consumption increases at faster rate! If you keep the speed down, then you can make the electricity to last longer.

Drag Effect

The mass of the vehicles is always inversely proportional to the efficiency of the vehicle. So, it is necessary to make the electric vehicle as light as possible in order to increase the range of the vehicle. We are not talking about stripping out the seats of the vehicle here, but must make sure that boot is not full of clutter. It is necessary to remove the racks and the bike holders from the roof racks because the slippery aerodynamics always improve the efficiency of the electric vehicle. It is a minor factor, but a car free of dirt and properly waxed will face less drag.

Figure 5: Drag acting on vehicle

Tires

It is suggested that approximately 25% of all the electric vehicles use improperly inflated tires. The use of the under-inflated tire does not only increase the energy consumption of the vehicle but it also results to produce the uneven or we can say the premature trend wear. So, it is necessary to frequently check the pressure of the tires with the help of the gauges. The change in temperature effect the tire pressure so it’s important to check the pressure regularly. The stickers attached to the side door frame usually have the information related to this. 

The use of the big alloy wheel results in increasing the rolling resistance of the vehicle. But, they result in reducing the efficiency of the electric vehicle. The use of the smaller wheel with the thick profile of the tire would increase the efficiency of the vehicle.

Auxiliary Sources

The operation of the air conditioning will reduce the battery range at faster rate. So, you must try to keep the compressor off when possible and to rely on the fan only. An alternative is to drive with the open window. The effect of window will be to increase the drag force acting on the vehicle and as the speed of the vehicle would increase, the drag force acting will also increase. Operation of the AC at full chill condition will drain the battery at a faster rate. Try to keep the car pre-cool in the summer months when you are charging the vehicle so that cooling does not rely on the batteries only.

Similarly, the use of the heater especially at the full blast will reduce the range of electric vehicle. It is necessary to dial down the climate control in the summer. Compared to large commercial heating, pre-heating your heated seats and heated steering wheel will use less energy. Heated seats do use a great amount of energy. One option is to pre-heat your vehicle while plugged in will increase its range.

Driving Behavior

Driving very fast will drain the electric car's battery at a faster rate. So, it is important to accelerate slowly when it is standing position. Moreover, try to keep the speed of the vehicle under 60 mph as most as possible. According to the Department of Energy, we can save 14% more energy by reducing the speed of the electric vehicle by 10mph. The eco mode in the vehicle is used to increase the range of the electric vehicle. 

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