Automotive Future: Electrified and Autonomous The Transition of an Industry

2.1 Project Objectives

2.2 Project Background

2.3 Sponsor Background

2.4 Sponsor Target Areas

2.4.1 Safe

2.4.2 Green

2.4.3 Connected

2.5 Project Terminology

2.5.1 Autonomous Vehicles (AV)

2.5.2 Electric Vehicles (EV)

2.6 Customer Needs

2.6.1 Autonomous Vehicles (AV)

2.6.2 Electric Vehicles (EV)

3.1 Problem Description and Critical Issues

3.2 Safety and Liability

3.3 Technology

3.4 System Components

3.5 “Connected” Vehicle Concepts

3.6 Traffic Management

3.7 Concept of Operations

3.8 Social Acceptance

SECTION 4. ELECTRIC PASSENGER VEHICLES (EV)

4.1 Problem Description and Critical Issues

4.2 Environmental Impact

4.3 Vehicle Component

4.4 Battery Types and Technologies

4.5 Vehicle Performance

4.5.1 Battery and Vehicle Efficiency

4.5.2 Energy Consumption

4.5.3 Battery Charging

4.5.4 Battery Lifetime

4.5.5 Battery End-Of-Life Issues

4.5.6 Operating and Life-Cycle Costs

4.6 Vehicle Safety

4.7 Concept of Operations

4.8 Social Acceptance

SECTION 5. CONCLUSIONS

SECTION 6. RECOMMENDATIONS

SECTION 7. REFERENCES

Automotive Future: Electrified and Autonomous

The Transition of an Industry
SECTION 1. EXECUTIVE SUMMARY
Autonomous vehicles have the possibility to completely change transportation methods. They will provide a safer, more environmentally conscious, and faster way to get to a destination. Although there are very obvious benefits to autonomous vehicles, there are some large barriers such as safety, privacy and liability that have the ability to hurt their introduction into society. It is important that the government puts clear guidelines in place to address these issues.

Electric vehicles are becoming better options for more consumers as the price decreases and the range increases. They impact the environment less than vehicles with internal combustion engines, and are safer to drive. With more help from the government and other major corporations, electric vehicles will be the new standard of transportation.

Identify technologies and opportunities to achieve the vision of safe and connected electric and autonomous vehicles.

Every day we’re hearing in the news about “vehicle of the future”, ones that will park themselves, drive themselves, talk to us, communicate with other vehicles and highway infrastructure, report data to insurance companies, and avoid accidents. In addition, many countries have announced recently that they will no longer allow the sales of gasoline or diesel automobiles after a certain date, e.g., Norway and The Netherlands in 2025, China and Britain in 2040. (Technically, the vehicles will need to be zero emission, which could include hydrogen and other technologies, but for the purpose of this project, the focus is on electric and autonomous vehicles).

What does this mean in terms of the technologies needed, societal acceptance, and the policies and supporting systems needed to enable these safe and connected electric and autonomous vehicles?

Vehicles of the future will utilize high power electrical drivetrains and wireless communications, which present challenges to the industry. For instance, high power electrical circuits can be safety concerns for consumers, mechanics, or first responders to vehicle accidents. Providing for their safety is critical for the industry. Wireless communication within the vehicle but also with other vehicles or traffic monitoring devices is an exciting opportunity to improve safety. However, there is risk with wireless communication that hacking might occur. Somehow this must be dealt with. How can these exciting new features be used without exposing people to high risks?

Delphi delivers innovation for the real world with technologies that make vehicles and trucks safer, more environmentally friendly, smarter, better connected, and more affordable than electric vehicles before.

Delphi Automotive is a global automotive components design and manufacturing company— it is one of the world’s largest automotive parts manufacturers and provides technology solutions for electrical, electronic, and safety systems to the global automotive and commercial vehicle markets. Delphi operates over 100 manufacturing facilities and 15 technical centers across 46 countries, utilizing a regional service model that enables it to serve its global customers. It has approximately 166,000 employees worldwide, including 20,000 engineers, scientists, and technicians. Delphi operates through two business segments:

Electrical / Electronic Architecture

Delphi provides complete design, manufacture and assembly of the vehicle’s electrical architecture, including connectors, wiring assemblies and harnesses, cable management, electrical centers and hybrid, high-voltage and safety distribution systems. Their products provide the critical signal distribution and computing power backbone that supports increased vehicle content and electrification, reduced emissions, and higher fuel economy.

Major products: Wiring harnesses, electrical centers, vehicle and cell phone wireless charging, data communication cabling, hybrid and all-electric vehicle charging systems.

Electronics and Safety

Delphi provides critical components, systems, and advanced software development for passenger safety, security, comfort, and vehicle operation, including body controls, infotainment and connectivity systems, passive and active safety electronics, autonomous driving technologies, and displays. Their products increase vehicle connectivity, reduce driver distraction and enhance vehicle safety.

Major products: Engine control module, advanced reception systems, navigation, displays, adaptive cruise control, radar and camera systems, parking guidance systems.
2.4 Sponsor Target Areas.
2.4.1 Safe.

Delphi envisions a society with zero road fatalities, zero injuries and zero accidents.

Delphi envisions a world with 50% less emissions.

Delphi is pioneering advancements in intelligent vehicle technology to deliver a seamlessly informed, personalized and safer driving experience.

SAE international has identified six levels of driving automation. The levels from 0 to 5 are no automation, driver assistance, partial automation, conditional automation, high automation and full automation. There is an important separation between levels two and three where it transitions from human drivers monitoring the driving environment to an automated driving system monitoring the driving environment. The job of the human in level two is to complete all tasks besides steering and acceleration/deceleration. The human should also be available to intervene if the system fails. Whereas for level three, the human does not need to perform any of these additional tasks, but should be ready to intervene if the system fails. After level three, the system will respond appropriately if there is a problem and there is no need for human intervention. Before level two, the human helps or completely controls the steering and acceleration/deceleration of the car. The levels range from human control to fully self-driving. Today, fully self-driving, autonomous cars are not common, but they are slowly being introduced into society despite some barriers.

There are three primary categories of electric vehicles (EV). Hybrid electric vehicles (HEV) are the most common electric vehicles. HEVs are primarily powered by an internal combustion engine that runs on conventional fuel and an electric motor that runs on energy stored in a battery. The battery is charged through regenerative braking and by the internal combustion engine; HEVs are not plugged in to charge.

Plug-in hybrid electric vehicles (PHEV) are powered by a conventional internal combustion engine and an electric motor that uses energy stored in a battery. All of these vehicles can operate solely on gasoline, but they can be plugged into an electric power source to charge the battery, and some can travel up to 70 miles on electricity alone. These vehicles are also called Extended-Range Electric Vehicles (EREVs).

Battery electric vehicles (BEV), or all-electric vehicles (EV), solely use electric energy to power the motor. They use a battery pack that can be recharged by plugging into an external power source. The U.S. Environmental Protection Agency categorizes BEVs as zero-emission vehicles because they produce no direct exhaust or emissions.

Customers need to be presented with a safe, well tested, government supported, private and cost-effective vehicle in order to be persuaded to purchase an autonomous vehicle.

Customers need an affordable vehicle that performs well, and does not contribute to the destruction of the environment.

Automated vehicles have issues dealing with unpredictable humans because their technology cannot control the actions of other humans. If a human driver were to not follow traffic laws around an automated vehicle, the automated vehicle must know how to respond accordingly. Weather is also a critical issue for automated vehicles because snow, mist, or rain can all obstruct their laser sensors thus preventing them from staying in their lane and putting its passengers in danger. Automated vehicles depend heavily upon highly detailed 3D maps that show stops signs, ramps, speed bumps, and much more. The issue with their reliance on these maps is that very few of these detailed maps have been made and roadways are constantly changing so the data the cars have on a road may no longer be accurate. The vehicles also have a problem distinguishing shadows on roads, for example a shadow could be a pothole, puddle, filled in pothole, oil spill or even just a shadow on a road. These uncertain shadows can cause the vehicle to unexpectedly slow down and possibly disrupt traffic flow. One of the biggest ethical issues with automated cars is how should engineers program their automated vehicles to make tough decisions. For example, if a child runs out into the road and the only options for the car are to keep going and hit the child saving the passenger or swerve out of the way and possibly kill the passenger and save the child. Automated vehicles may face problems in their creation but they are still needed. About 1.3 million people die in road crashes each year, which is on average 3,287 deaths a day. An additional 20-50 million are injured or disabled. With a successful automated vehicle design over time the number of deaths due to car crashes could diminish, thus saving many lives and preventing injury. Without injury due to car crashes this would reduce hospital stays and increase production in the economy because workers would not have to take off because of injury.

In order to ensure maximum safety, autonomous vehicles must utilize all three main types of sensors: vision (cameras), radar, and LiDar. By using all three, there will be redundancies in the system, which will lower the chance of failure overall. Autonomous vehicles have the potential to dramatically reduce crashes. Figure 1 shows a possible model of an autonomous vehicle. This model has multiple cameras, in the front, back and top of the car, and a main sensor on top. Companies must develop a system that can sense objects in the road and also drive in poor weather conditions. Today, most car accidents are caused by human error. Because of this, autonomous vehicles will prove to be safer than human operated vehicles. It is important to have well developed cyber security in order to avoid any outside attacks. There should also be initial tests done on develop systems to see exactly how much autonomous vehicles should be held accountable. The current safety regulations are outdated so it is necessary to create new regulations in order to stay up to date with the current technology. At the moment, a well thought out liability framework has not been addressed by the government. As soon as this happens, more people will be willing to accept AVs, because as of right now there is a lot of uncertainty on who would be held accountable in the face of a crash. Since, autonomous vehicles do have many sensors, they should be able to make decisions at a faster speed than humans. This might cause manufacturers to be more at fault if a problem arises.

In order for the automated vehicle to be able to properly interact with its environment, various technologies are needed such as long-range radar, LIDAR (laser scan), cameras, short/medium-range radar, and ultrasound. The cameras allow the vehicle to examine traffic signals such as a stop light or cross traffic warnings. Automated cruise control uses long-range radar and laser systems to calculate the distance and speed of other cars surrounding them in their environment. To avoid traffic automated cars will also collect data on their surrounding environment and change course accordingly. LIDAR lasers will be used to detect pedestrians, potholes, and to avoid collisions. Ultrasound will assist in automated parking. Short to medium range radar will be used mainly to avoid collisions and objects in its blind spot.

The systems of the automated car will be automated cruise control, automated parking assistance, Automated Highway Driving Assistant, Autonomous Highway Driving. All of these contain one or more of the various technologies used. Automated cruise control uses long-range radar and lasers. Automated parking assistance uses cameras and ultrasound to detect surrounding objects. Sensors are used in autonomous highway driving. The components of these systems can be viewed in Figure 3.

The vehicle of the future should be optimally connected to maximize the driver’s and passengers’ experience while minimizing the driver’s distraction. Connecting the vehicle itself and all its sensors to the outside world should not be overlooked. The vehicle of the future will have 100s of sensors collecting data, which may be very beneficial to others. For example, if a vehicle is doing 5 mph on a 65-mph interstate, an algorithm would determine a traffic jam was present and alert other approaching vehicles of the situation. The brakes could be applied for very close vehicles, or navigation systems could re-route approaching vehicles to avoid the congestion. Today’s driving assistance systems are the stepping stones to fully autonomous vehicles.

One quarter of all accident occur at intersections, so it is necessary to develop software for autonomous vehicles that will combat this issue. The autonomous intersections will operate in similar way to air traffic control, so each car will receive a specific time slot when they can pass through the intersection and will therefore slow down or speed up in order to meet that time slot. One proposed software was developed by Peter Stone called Automated Intersection Management (AIM). While using AIM, the car will use Dedicated Short Range Communication (DSRC) to communicate with the intersection manager to reserve a spot in the intersection. The intersection manager will grant access to the car if there are no potential collisions projected. If a possible collision is spotted, the intersection manager will require some cars to wait their turn. This new software will lower the number of cars that have to slow down and speed up at intersections which will therefore reduce traffic congestion, fuel use and harmful emissions. Figure 7 shows a possible bird's eye view of an intersection that uses AIM. In the figure, it shows the possibility of having multiple cars in an intersection at once with a small chance of collisions. Another idea is called Light Traffic, which was developed by a group from MIT. This would link all autonomous cars to a cloud-based program that would track their movements and set their speeds. Therefore, the cars would go through the intersections in groups instead of one by one, which could lead to a slightly longer delay for individual cars, but would be more efficient overall. Both these ideas will only work if all of the vehicles in the intersection are autonomous.

Operational needs of the automated vehicles are that the vehicle needs to be able to sense objects, other vehicles, and pedestrians in the surrounding environment so the car can avoid damage and collisions. The sensors also need to be able to register what in the surrounding environment is near and far. Being able to follow traffic laws and signs is also an operational need, along with gathering information on the best route to take to get to the destination to avoid traffic and other road blockages. The operational concept of these vehicles is for the car to drive without assistance from the passenger and be just as or even more safe than if there was a driver. The vehicle needs to be operational during inclimate weather so the sensors and cameras must be adapted to still be of use in this weather. The operational scenarios of black ice, fog, snow, or rain this could all obstruct the automated vehicles operating systems. More advanced and exact lasers, cameras, radar and various other technologies will be improved to combat these issues. The user needs are for user-system interaction in a day to day basis of travel from their home to wherever they may desire and back with efficiency and ease. Even though the vehicle is self-automated the users can still interact with the vehicle in many ways such as playing music, interacting with the route chosen, view data on their route, and can the user can interact through voice and touch control. Possible user-system interactions can be seen in Figure 5. The stakeholders are the researchers and designers who are responsible for creating the software and technology of the car, the owners of the business who make many decisions on what the design should be, and the users who will use the vehicle in their daily lives. The current viewpoint of autonomous vehicles is that they are not as safe as they could be, however the stakeholder’s expectations are that it should be even more safe than when there is a driver. The improvement to be made is more tests with new and advanced technologies to see how the vehicle reacts in different environments.

General public acceptance of autonomous vehicles proves to be the biggest barrier in introducing them into society. Although the general public sees the positive effects of autonomous vehicles such as productivity, efficiency and the environmental impact, it's evident that the possible negative impacts are dissuading people from using autonomous vehicles. These negative impacts include the safety, law and cost of the vehicles. People are wary that they might not be able to afford autonomous vehicles, but companies are still trying to find a way to make the cars economically viable for the general public. It is obvious though, that technology and laws must be further developed in order to have a larger percentage of people buy autonomous vehicles. People worry about possible computer malfunctions and the lack of control that they would have over their cars. This is why more people are keener to the idea of having semi-autonomous vehicles, so in the case of a computer malfunction, the human can take over control. This distrust of computers increases with age, so people of the younger generation are proven to be more open to the idea of autonomous vehicles as seen in Figure 9. 37% of people ages 18-25 that were asked would consider buying an autonomous vehicle, while only 9% of people ages 57-65 would consider buying one. This figure also shows that men are also more likely to buy a self-driving car than females. Another reason why people are unsure about autonomous vehicles is that they believe the government will use this technology to spy on them and track their location. This lowers people’s sense of privacy and security. Finally, people are upset about the introduction of autonomous vehicles, because they like driving and don’t want this ability to be taken away. Therefore, social acceptance will prove to be the largest barrier in successfully introducing autonomous vehicles to the general public.

There are more problems and issues with electric vehicles than most people might know. The two main resources that are composed of in electric vehicles are lithium for the batteries and cobalt. Within the next 3 years the demand for cobalt is supposed to increase by 40% and 50% for lithium. Simpler problems include charging station and the complexity of those. Each stand is different and with that comes different charging speeds and many vary greatly in price. A more common problem with charging stations are regular cars being parked in one of the few spots that you can charge your electric vehicle.

For companies like Tesla to get the rare metals needed to complete their electric vehicles and those rare metals only exist in small quantities. To get those metals, it requires an excess of work. In some cases, there have been 8ft holes dug just for a small portion of that metal. With that small portion of it, scientists have found that using various acid baths that they can use .2% of the materials that have been pulled out of the ground while the other 99.98% is contaminated with toxic acids.

Every different car and brand will have a variety of different components within the vehicle. The most common component is the electric motor. Each car will have a different size motor and different components inside it to fit the needs of the car that you are driving. Another major component is the controller, also known as the gas and brake pedal. That is what causes the car to accelerate or decelerate. The most widely known component of an electric vehicle is the batteries. They use Lithium-ion batteries and those are made up of rare metals and pieces which will someday become scarce. Figure 4 shows a components diagram for an electric vehicle.

Lithium-ion batteries are currently used in most portable electronics such as cell phones and laptops because of their high energy per unit mass relative to other electrical energy storage systems. They have a high power-to-weight ratio, high energy efficiency, good high-temperature performance, and low self-discharge. Also, most components of lithium-ion batteries can be recycled. Today, most PHEVs and BEVs use lithium-ion batteries. A lithium-ion battery produces a charge from the movement of ions from the positive and negative electrode. Charge cycling, elevated temperature, and aging decrease battery performance over time. Manufacturers specify the life of lithium-ion batteries in most consumer products between 300 and 500 charge cycles. Figure 8 illustrates the capacity drop of 11 lithium-ion polymer batteries that have been cycled at a Cadex laboratory. The batteries averaged over 10 percent capacity drop after 250 cycles. Lithium-ion batteries also lose capacity when stored at higher temperatures. Lithium-ion batteries are estimated to have a lifespan of 2-3 years, but this includes the shelf life.

Nickel-metal hydride (NiMH) batteries are used primarily in computer and medical equipment, but they have been successfully used in BEVs and are widely used in HEVs. NiMH have a much longer life cycle than lead-acid batteries and are very resilient to abuse. The main problems with nickel-metal hydride batteries are their high cost, high self-discharge and heat generation at high temperatures, and the need to control hydrogen loss.

Lead-acid batteries can be designed to be high power and are inexpensive, safe, and reliable. However, low specific energy, poor cold-temperature performance, and short calendar and cycle life impede their use. Advanced high-power lead-acid batteries are being developed, but these batteries are only used in commercially available electric drive vehicles for ancillary loads.

EVs convert about 59%-62% of the electrical energy from the grid to power at the wheels. Conventional gasoline vehicles only convert about 17%-21% of the energy stored in gasoline to power at the wheels. Electric vehicles produce peak torque at zero RPM, meaning acceleration figures tend to be stellar. It’s because of that low-end torque (and just generally high torque output across a large rev range), low inertia, and high redlines that electric motors tend to be mated to single-speed gearboxes instead of complex transmissions. This means less weight in the drivetrain, more reliability, and no drivability or acceleration sacrifices associated with shifts. The range of an electric vehicles is typically limited to 60 to 120 miles on a full charge although a few models can go 200 to 300 miles.

EV batteries typically hold 24 kilowatt-hours(kWh), but Tesla Motors has 60 kWh and 100 kWh models. The average energy efficiency for city driving is 27 kWh/100-mile and 28 kWh/100-mile for freeway driving.

There are three categories of electric vehicles charging. Level 1 is a cord-set connect to a regular household outlet (115VAC, 15A). This single-phase hookup produces about 1.5kW, and the charge time is 7 to 30 hours depending on battery size. Level 1 meets overnight charging requirements for e-bikes, scooters, electric wheelchairs and PHEVs not exceeding 12kWh. Level 2 is a wall mounted, 230VAC, 30A two pole unit. It is the most common home and public charging station. It produces about 7kW to feed the 6.6kW on-board electric vehicle charger, charging the battery in 4-5 hours. Level 3 is a DC fast charger. It puts 400-600VDC, up to 300A; it bypasses the onboard charger and feeds power directly to the battery. Level 3 chargers deliver up to 120kW to fill a Li-ion battery to 80 percent in about 30 minutes. This power demand is equivalent to five households. Figure 6 shows a user charging an electric vehicle with a level 2 charger.

Although batteries are designed for extended life, they eventually wear out. Most manufacturers are offering 8-year/100,000-mile or 70 percent capacity warranties for their batteries.

Four factors affect the life of a Li-ion battery. High temperatures, overcharging or high voltage, deep discharges or low voltage, and high discharges or charge current. When a lithium battery is charged, the voltage slowly rises. When it reaches full charge, voltage is at its highest and will not go up any more. There’s a need to keep voltage from getting excessive, which is why batteries come with a battery management system (BMS). A BMS controls the charging voltage so maximum charging voltage and temperature is never exceeded. After 10 years many companies claim their batteries will have 70 percent capacity.

There is significantly less maintenance required on electric vehicles because there are fewer fluids to change, brake wear is significantly reduced due to regenerative braking, the battery requires little to no maintenance, and there are fewer moving parts relative to a conventional gasoline engine.

Commercially available electric-drive vehicles must meet the Federal Motor Vehicle Safety Standards and undergo the same rigorous safety testing as conventional vehicles sold in the United States. HEVs, PHEVs, and electric vehicles have high-voltage electrical systems that typically range from 100 to 600 volts. Their battery packs are encased in sealed shells and meet testing standards that subject batteries to conditions such as overcharge, vibration, extreme temperatures, short circuit, humidity, fire, collision, and water immersion. Manufacturers design these vehicles with insulated high-voltage lines and safety features that deactivate the electrical system when they detect a collision or short circuit. Electric vehicles tend to have a lower center of gravity than conventional vehicles, making them more stable and less likely to roll over. Electric drive vehicles are designed with cutoff switches to isolate the battery and disable the electric system, and all high-voltage power lines are clearly designated by being colored orange for emergency responders.

Consumers need a product that will perform as well as current gasoline cars on the market without producing harmful emissions. They need these vehicles to perform daily driving in all conditions. The user must easily be able to charge the unit in a timely manner, and not worry about maintenance on the car. The current market for electric vehicles is wealthy individuals who prioritize innovation and creativity over utility. As electric vehicles continue to decrease in price, more demographics will be able to enjoy the benefits of electric vehicles. Increasing the public infrastructure to charge electric vehicles will also help these vehicles reach larger demographics.

There is a gap between consumer expectations and electric vehicle performance. The general public views 4-5 hours as an absurd recharge time. Consumers do not want to pay the premium for an electric vehicle, and they become less interested as fuel economy for gasoline engines continues to increase. Consumers also expect a range of 300 miles to purchase over conventional cars. Figure 10 shows the increase of electric vehicle sales from 2014-2017. Finally, if electric vehicles are going to be widely adopted, there needs to be more public charging infrastructure.

• 
  https://www.sae.org/misc/pdfs/automated_driving.pdf
  
• 
  https://www.nytimes.com/interactive/2016/06/06/automobiles/autonomous-cars-problems.html
  
• 
  http://asirt.org/initiatives/informing-road-users/road-safety-facts/road-crash-statistics
  
• 
  https://groups.csail.mit.edu/mac/classes/6.805/student-papers/fall14-papers/Autonomous_Vehicle_Technologies.pdf
  
• 
  https://www.delphi.com/media/blog/how-do-we-use-ai-for-our-automated-vehicles
  
• 
  https://www.trafficsafetystore.com/blog/autonomous-car-technology/
  
• 
  http://www.cs.utexas.edu/~aim/
  
• 
  https://spectrum.ieee.org/cars-that-think/transportation/self-driving/the-scary-efficiency-of-autonomous-intersections
  
• 
  https://web.wpi.edu/Pubs/E-project/Available/E-project-043013-155601/unrestricted/A_Study_of_Public_Acceptance_of_Autonomous_Cars.pdf
  
• 
  https://www.google.com/url?q=https://www.afdc.energy.gov/vehicles/electric.html&sa=D&ust=1512440092375000&usg=AFQjCNHEtjkLTusc8pp0ScBtXu7qPSmPDg
  
• 
  https://www.google.com/url?q=https://www.trafficsafetystore.com/blog/autonomous-car-technology/&sa=D&ust=1512440092371000&usg=AFQjCNF3Y3xuWPyMNt3ficKALJp_gh8_xw
  
• 
  https://www.google.com/url?q=https://web.wpi.edu/Pubs/E-project/Available/E-project-043013-155601/unrestricted/A_Study_of_Public_Acceptance_of_Autonomous_Cars.pdf&sa=D&ust=1512440092384000&usg=AFQjCNEoXnoLnJ9mOqO87nV32PpYwx-SDA
  
• 
  https://www.google.com/url?q=https://www.cheatsheet.com/automobiles/5-biggest-problems-electric-vehicle-charging.html/?a%3Dviewall&sa=D&ust=1512440092386000&usg=AFQjCNFwJDX9KiqTTOZhDjerIrBfiWqucg
  
• 
  https://www.google.com/url?q=https://www.wired.com/2016/03/teslas-electric-cars-might-not-green-think/&sa=D&ust=1512440092387000&usg=AFQjCNFeKR3CvpufF5rWG10dAIxuC4PnaA
  
• 
  https://www.google.com/url?q=http://www.gavinshoebridge.com/electric-car-conversion/the-three-main-parts-of-an-electric-car/&sa=D&ust=1512440092385000&usg=AFQjCNE8zTjDNfyMjOyFPG-vfui0U_Anpw
  
• 
  https://www.google.com/url?q=https://www.afdc.energy.gov/vehicles/electric_batteries.html&sa=D&ust=1512440092393000&usg=AFQjCNHPcO4XR4V6GMKpvaJWjo_erUIgAg
  
• 
  https://www.google.com/url?q=http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries&sa=D&ust=1512440092393000&usg=AFQjCNHfvr5aZWVc3Q-kUxeD4Ht0SlzwnQ
  
• 
  https://www.google.com/url?q=https://www.fueleconomy.gov/feg/evtech.shtml&sa=D&ust=1512440092372000&usg=AFQjCNF49UJ6WBr-Fw0N-TVY185sa6P3iQ
  
• 
  https://www.google.com/url?q=https://www.sciencedirect.com/science/article/pii/S1361920914001485&sa=D&ust=1512440092381000&usg=AFQjCNHKBqMuFgGCyW0qyz8sV-J4ecqthA
  
• 
  https://www.google.com/url?q=http://batteryuniversity.com/learn/article/bu_1004_charging_an_electric_vehicle&sa=D&ust=1512440092379000&usg=AFQjCNE21fnhdMF1wuom1pma-We68h9WEg
  
• 
  https://www.google.com/url?q=https://energy.gov/eere/electricvehicles/electric-car-safety-maintenance-and-battery-life&sa=D&ust=1512440092380000&usg=AFQjCNEwsWCTV4JuK6kAfjujBG0dtLkGwg
  
• 
  https://www.google.com/url?q=https://www.fleetcarma.com/todays-electric-car-batteries/&sa=D&ust=1512440092372000&usg=AFQjCNGb6jdI1__xSaHWtUT4iMF2t6Z0Mg
  
• 
  https://www.google.com/url?q=https://www.afdc.energy.gov/vehicles/electric_maintenance.html&sa=D&ust=1512440092375000&usg=AFQjCNFVWTNpuWlDpy4bBe3D7V4a5PZ8qQ
  
• 
  https://www.google.com/url?q=https://www.epa.gov/sites/production/files/2014-09/documents/kodjak121312.pdf&sa=D&ust=1512440092392000&usg=AFQjCNH4OTIQhCA1QgQ9iNAp19mDu_XKpg