Hybrid Electric Vehicle – Down to the Parts

With all the great news from the auto industry introducing another hybrid vehicle or another electric vehicle, this article explores a bit what such vehicles are made of. What are the differences with the conventional petrol car and what might the future hold for them?

The first difference you see these days is that both the electric vehicle and the hybrid vehicle come with a plug to charge it at home; the conventional vehicle has not. The conventional vehicle also has no electric engine to power the wheels or a large battery to power this engine. The conventional car of course does have a battery, but that is just used for starting the internal combustion engine and it acts as a buffer for the electrical systems used. Power in the conventional vehicle is generated by the combustion engine.

For an electric vehicle, there are two main components: the electric motor and the battery. The electric motor is the one to power the wheels of the vehicle and the battery is used to bring along energy for the trip. They almost all have the option of regenerative braking, which allows one to recover energy when slowing down and charging the battery a little while doing so. This is a great method to increase the overall efficiency for a vehicle! Further more there is often a special battery management system (BMS) which ensures the battery is kept at the right temperature and is not charged or discharged in a way that can damage the battery.

For a hybrid vehicle there are a few more main components: besides the electric motor and the battery, there is also an onboard power source like the conventional combustion engine (but also a fuel cell is used for example). Additionally, there is a system that somehow connects the power from the battery and the for example combustion engine and gets it to the wheels. There are many ways to do this last step, the simplest being that the combustion engine would be used as a generator to power the electric motor with electricity. Excess electricity is stored in the battery for future use. Another method is to have a special gear set combine the mechanical power from the combustion engine and the electric engine and get them to the wheels. There are also manufacturers who power one set of wheels with the combustion engine and the other set of wheels with the electric engine. A big advantage of the hybrid vehicle is that it can use the very efficient electric engine at lower speeds (for example urban areas) and the combustion engine for extra power on the highways or for extra range.

To sum it up, an electric vehicle consists of:

– Electric Engine
– Battery

A hybrid vehicle consists of:

– Electric Engine
– Battery
– Energy source (internal combustion engine, fuel cell, etc)

The disadvantages of the electric vehicle and the hybrid are mostly the cost. Compared to the conventional car they can cost more to purchase. This has two main reasons; the first being that the conventional car is mass-manufactured which makes it cheaper (compare one million units produces versus one thousand units produced) and the second is the current price of batteries. Batteries at the moment are the biggest cost within the vehicle, the larger your battery is, the larger the cost is in the total price of the vehicle.

Another disadvantage which currently mostly applies to the electric vehicle, is the range it can cover. Current vehicles are of such a weight and their batteries can only hold a certain amount of power. Comparing the electric vehicle to a conventional petrol car they can cover a lot less ground on a full charge or tank. The first argument to counter this disadvantage is that most people do not drive distances that can not be covered by an electric vehicle. Current electric vehicles can cover about double or four times the daily distance required by many people! However, there are three movements currently helping to overcome the range anxiety problem. The first is the battery manufacturer, which improves the technology so that the battery will weigh less and can contain more power. The second is the charging industry, where solutions are found in fast charging. Conventional charging can take up to eight hours to charge your vehicle. The goal is to reduce this to an acceptable amount of mere minutes. The third force is heading for battery swapping; much like a petrol station, an electric vehicle can swap the empty battery for a fully charged one.

For the future of the electric vehicle and the hybrid there are many options, the most popular ones are:

– Fuel Cells
– Fast Charging of batteries
– Better batteries that weigh less and hold more power
– Battery swapping stations
– New car design options

Lots to expect from the electric vehicle and the hybrid vehicle!

EV Basics II – An Electric Vehicle Primer

Important Acronyms:

BEV – Battery electric vehicle, a vehicle which uses only batteries and one or more motors to provide the force that makes it go.

EV – Electric vehicle, any vehicle that uses electric power to provide some or all of its propulsive force.

FCEV – Fuel cell electric vehicle, an electric vehicle which uses a hydrogen fuel cell as its source of electric power.

HEV – Hybrid electric vehicle, a car or truck that uses both an ICE and an electric motor.

ICE – Internal combustion engine, the powerplant of choice for the dirty, inefficient vehicles of the 20th Century.

PHEV – Plug-in hybrid vehicle, a hybrid vehicle with a battery pack that can be charged from a wall socket.

Have you just developed an interest in electric vehicles? Are you looking to learn some EV fundamentals? You’ve come to the right place! Read on, and you will start your education on the wonders of EVs. In this article, I will introduce readers to some of the various different types of EVs and explaing some of the advantages and issues associated with each type. Note that this article is only an introduction. I will go into more depth on different aspects of the subject matter in future installments of the “EV Basics” series.

There are several different power trains available which use electric motors. The simplest of these vehicles is the battery electric vehicle or BEV. This is a pure electric vehicle which uses only a battery pack and an electric motor to store energy and create the power necessary to make the car or truck move. BEVs have been around for a long time. In 1835, Thomas Davenport built a railway operated by a small electric motor. In the early years of the 20th Century, BEVs competed quite successfully with ICE-powered vehicles. It was not until Henry Ford started building the Model T that gasoline-powered cars that BEVs faded from public view.

In the 1960s, BEVs began to make a comeback. Interest in electric vehicles has grown steadily since then as concerns about pollution and dependence on foreign oil have permeated mainstream consciousness. Currently, BEVs are being designed and built in a wide variety of styles and layouts, from electric scooters, to low-speed electric cars such as those produced by Zenn Motor Company, to high-power freeway burners such as the two-seat Tesla Roadster or the family-friendly, five-passenger eBox by AC Propulsion.

BEVs must face a few hurdles if they are to replace ICE-only cars as our primary method of transportation. Historically, they have had limited driving range, significantly less than the range of a gasoline-powered car. Additionally, BEV have generally taken several hours to recharge the battery pack. In a world in which people have gotten used to instant gratification, this poses a real problem. The good news is that many people are working on these issues, and dramatic improvements are being made in both range and recharging time. Current EV designs have achieved ranges of more than 300 miles and charging times have been brought down to two hours or less in some models charged with high-powered “smart” chargers.

In the 1990s, Honda and Toyota introduced the American driving public to the hybrid electric vehicle or HEV. These vehicles use both an ICE and an electric motor. There are different types of HEVs which layout the engine and the motor in either a parallel or a series configuration. In a series configuration, the ICE acts only as an electrical generator. In a parallel configuration the ICE again acts as a generator, but it also drives the vehicle’s wheels just as the engine would do in an ICE-only vehicle.

HEVs provide significant benefits over ICE-only cars in two distinct areas. Firstly, the electric motor allows engineers to operate the ICE more efficiently because an HEV can rely heavily on the electric motor at points in which the ICE would be operating very inefficiently. Secondly, the battery pack in an HEV can be used to recapture the energy used while braking. To accomplish this, engineers create regenerative braking systems which used the electrical resistance of a generator to slow the car down long before they mechanical brakes come into play. The energy from the generator is then stored in the battery pack for future use. In a car without regenerative braking, all this energy is wasted by creating heat and wearing down the brake pads.

HEVs also have some problems. Unlike BEVs, they require some gasoline or other liquid fuel to operate. Also, they are more complicated then either a BEV or an ICE-only vehicle because they require both types of drivetrain components under one hood. However, they eliminate the range and recharging issues associated with BEVs, so HEVs can be viewed as a good transition step to the vehicles of the future.

Recently, much attention has been paid to plug-in hybrids or PHEVs. In essence, a PHEV is an HEV with a larger battery pack, a plug which allows the battery pack to be charged from a wall socket, and a control system which allows the vehicle to be operated in electric-only mode. The wall-charging feature allows a PHEV to get some of its power from the utility grid (or from a local power source such as a photovoltaic array or wind turbine) and some of its power from gasoline. Recently, several companies and individuals have been working on creating plug-in versions of the Toyota Prius. These conversions allow the Prius to run in all-electric mode until it reaches roughly 35mph. They give varying traveling ranges in all-electric mode, depending on which type of batteries are used and how many extra batteries are installed.

While these plug-in Priuses are a good start, PHEVs as a genre have even more potential. General Motors recently introduced the Chevrolet Volt E-Flex concept car, a PHEV which can travel up to 40 miles in electric only mode. It has a large electric motor and a one liter, three cylinder ICE. PHEVs of the future could follow this trend even further, maximizing the electric elements of the drivetrain while reducing the ICE to a tiny power plant which gets used only as a last resort.

In the last few years, fuel cell electric vehicles or FCEVs have grabbed many headlines. These are electric vehicles which use a hydrogen fuel cell to provide power, eliminating the need for a battery pack. Proponents point out that hydrogen is the most abundant of the chemical elements and that the only gas emitted from an FCEV is steam made from pure water. Detractors point out that nearly all hydrogen currently available is made from natural gas, a petroleum product. Hydrogen is also difficult to store in quantities sufficient to give FCEVs adequate range and it can present safety hazards when pressurized in tanks. Finally, FCEVs currently require complex, bulky support systems which take up excessive space and result in power delivery systems which are far less efficient than those present in BEVs.

Fuel cells have some potential to become part of the overall energy scenario in the future. However, many feel that FCEVs have been used primarily as a distraction and a stalling device. Companies and politicians keep telling us, “We’ll have FCEVs in the near future, but until then keep driving your Hummers!” These tactics keep people from demanding BEVs as soon as possible. As one saying puts it, “Practical, viable fuel cells are ten to twenty years away, and they always will be.”

One other type of electric vehicle is the human-assist hybrid. The most common example of this vehicle type is the electric bicycle. These are commonly-available, inexpensive, and they give people the health benefits associated with exercise while providing an additional boost when needed. Legally, they must be limited to 20 mph in electric assist mode, and the electric-only range of electric bikes now available is almost always less than twenty miles.

However, readers should ponder the fact that a small, aerodynamic vehicle can cruise at 65 mph on a flat road while using only five horsepower. Imagine the roads covered with small, efficient vehicles that use tiny electric motors and human power to achieve freeway speeds without putting a significant burden on the utility grid. While no major corporations are working on vehicles like this, small groups of dedicated individuals are working to make this type of vehicle available to the general public. These low-power vehicles could become the ultimate transportation solution for an energy-conscious society.

So there you have it! You now have enough information to join EV-related conversations at your next social gathering. You can talk about the different types of EVs, letting people know what is available now and what is coming in the near future. If you are still curious for more details on the benefits of electric vehicles and the advances which are being made in the field, please see the other articles in this “EV Basics” series.

Batteries – The Heart of the Electric Vehicle Conversion

The batteries are truly the heart of the EV conversion! Getting the right batteries for your ev conversion is essential and will ensure that you have many years of service from your converted vehicle. Deep cycle lead acid batteries, which can be further divided into flooded and sealed batteries, are used the most in electric vehicle conversions for the following reasons:

1. Deep cycle lead acid batteries are able to withstand repeated heavy discharging up to 30% of their capacity. They are able to withstand discharging to deeper levels for short periods of time, although this will affect their lifespan adversely.

2. Flooded Deep Cycle lead acid batteries are comparatively cheap, compared with other types of batteries and will last for quite a long time if you take care of them and do not discharge them beyond 30% of capacity and recharge them well when they are discharged.

3. Sealed Deep Cycle lead acid batteries are lighter than flooded batteries, which is beneficial when doing conversions with small vehicles and possibly some higher performance vehicles. They also do not need to only be placed upright and can therefore be placed into positions which are not possible with flooded lead acid batteries.

When considering which batteries to purchase for your electric vehicle conversion other factors which you should consider are:

1. The Life Cycle Cost
This is the initial cost of the batteries over the lifespan of the batteries, and can be a significant factor in determining which battery to use

2. Initial Cost Range
This is the initial cost of the batteries over the anticipated range, which can be used in conjunction with the life cycle cost in deciding which battery to use.

3. The Energy Density
This is amount of energy contained in a specific amount of the fuel source, that is the battery. Measured in watt-hours per pound, or watt-hours per kilogram it is a good way of determining which battery will best suit your conversion.

4. The amount of maintenance required.
Servicing an electric vehicle is not nearly as demanding as servicing a regular gas vehicle, however it is necessary to pay careful attention to the batteries in your electric vehicle as properly maintained batteries will last longer and therefore be cheaper per mile travelled.

As the batteries represent a considerable cost factor in your ev conversion you should carefully consider all these facts before choosing the batteries for your electric vehicle. And when you have made the decision and bought your battery set for your electric vehicle, be sure to take good care of them and then you will enjoy many miles of carefree and low cost traveling with your new electric vehicle. Enjoy the EV Grin!