CHAPTER 7

HYBRID AND ELECTRIC VEHICLES

LEARNING OBJECTIVES KEY TERMS After studying this chapter, the reader will be able to: BEV

1. Describe the different types of hybrid electric vehicles. Combined charging system (CCS) 2. Explain how a hybrid vehicle is able to achieve DC Quick Charger (DCQC) an improvement in fuel economy compared to a conventional vehicle design. (EV)

3. Discuss the advantages and disadvantages of the Hybrid electric vehicle (HEV) various hybrid designs. Internal combustion engine (ICE) 4. Describe HEV components, including motors, energy sources, and motor controllers. Plug-in hybrid electric vehicle (PHEV) 5. Discuss the operation of a typical hybrid electric vehicle. Range anxiety 6. Identify a plug-in hybrid electric vehicle (PHEV) Zero-emission vehicles (ZEVs) 7. Explain how the high-voltage batteries are recharged in a PHEV and EV vehicle 8. Discuss range anxiety 9. Discuss the battery capacity and range correlation of an EV 10. Describe the levels of chargers used to charge a PHEV or an EV . BACKGROUND In the late 1990s, several vehicle manufacturers produced electric vehicles, using electronic controllers to meet the Early Electric Vehicles demands for zero emission vehicles as specified by law in California at the time. Electric vehicles were produced by Early electric vehicles (EV), also called battery electric Ford, Toyota, Nissan, and General Motors. vehicles (BEV), were first used in the late 1800s, and it was not until the early 1900s that electric vehicles were practical Legislation was passed in California that included the following using rechargeable lead–acid batteries. revisions within the zero emissions vehicle (ZEV) mandate. As a direct result of the California zero-emission vehicle mandate • One the first was the 1903 Baker Electric , produced originally calling for 10% ZEV, General Motors developed by the Baker Motor Vehicle Company in , the electric vehicle 1, known as EV1, and it was leased to Ohio. customers in California and Arizona. SEE FIGURE 7–1. • The Detroit Electric Car Company (1907–1939) produced very practical fully electric vehicles. The old electric vehicle mechanical controller was able to switch all six batteries in various combinations of series and parallel configurations to achieve lower voltage for slow speeds and higher voltages for higher speeds. Electric vehicles did not have a long range and needed to have the batteries charged regularly, which meant that electric vehicles could only be used for short distances. In fact, electric vehicles were almost more popular than steam power in 1900 when steam had 40% of the sales and electric had 38% of the sales. The gasoline-powered represented only 22% of the vehicles sold.

Figure 7-1 View of the components of the General Motors electric Early Hybrid Electric Vehicles vehicle (EV1). Many of the features of this vehicle, such as A hybrid electric vehicle (HEV) vehicle is one that uses two regenerative braking, currently used on hybrid vehicles were first put different methods to propel the vehicle. A hybrid electric vehicle into production on this vehicle. uses both an internal combustion engine and an electric motor to propel the vehicle. In 1901, Ferdinand Porsche developed the Lohner-Porsche Mixte Hybrid, the first gasoline-electric hybrid automobile in the world. It was originally an electric- HYBRID ELECTRIC VEHICLES powered vehicle and then a gasoline engine was added to recharge the battery. One of the first hybrid electric car was Definition of Terms produced by the Owen Magnetic Motor Car Corporation, Most hybrid vehicles use a high-voltage battery pack and a manufactured in New York City and then in Wilkes-Barre, PA, combination electric motor and generator to help or assist a from 1915 until 1922. It failed because the fuel economy was gasoline engine. The internal combustion engine (ICE) used about the same as a conventional gasoline powered vehicle in a hybrid vehicle can be either gasoline or diesel, although yet cost more. Another vehicle that used both a gasoline only gasoline-powered engines are currently used in hybrid engine and an electric motor to power the vehicle was built by vehicles. An electric motor is used to help propel the vehicle, Woods Motor Company of , , and was called and in some designs, it is capable of propelling the vehicle the “Woods Dual Power” (1915–1918). alone without having to start the internal combustion engine.

Newer Electric Vehicles First Widely Produced Hybrids Due to the oil embargo of 1973 and an increased demand for The hybrid electric vehicle did not become widely available alternative energy sources, Congress enacted Public Law 94- until the release of the Toyota Prius in Japan in 1997, followed 413, the Electric and Hybrid Vehicle Research, Development, by the Honda Insight sold in the starting in 1999. and Demonstration Act of 1976, which was designed to Then in 2001, the first Toyota Prius was introduced in the promote new technologies. United States. By 2010, there were several electric vehicles for sale although often in limited parts of the country and in limited numbers. Electric vehicles include the Tesla, Nissan Leaf, and Chevrolet Volt. SEE FIGURE 7–2. ONE, TWO, AND THREE MOTOR SYSTEMS One-Motor Hybrids Hybrid electric vehicles that use one electric motor include VW, Nissan, Honda, and General Motors. In these units, an electric motor is attached to the ICE (engine) crankshaft and is used to perform two functions:

1. Start the ICE engine 2. Act as a generator to charge the high-voltage batteries.

Figure 7-2 The Chevrolet Volt is charged through a port located at General Motors also uses a belt alternator starter (BAS) the left front. system, which uses a belt-driven motor/generator attached to the front of the engine. Hybrids that use one motor are LEVELS OF HYBRID VEHICLES often called mild hybrids and usually are not able to power the vehicle using electric power alone. The term hybrid refers to a type of vehicle. However, there are different levels of “hybridization” among hybrids on the market. Different vehicle manufacturers use various hybrid Two-Motor Hybrids technologies. Hybrid electric vehicles that use two motors are the most commonly used hybrids by Toyota, Ford, and General Motors Mild Hybrid in their full-size two-mode trucks. Each electric motor serves two purposes: A mild hybrid will incorporate idle stop and regenerative braking but is not capable of using the electric motor to propel the 1. The motor/generator attached to the engine, usually vehicle on its own without help from the internal combustion labeled M/G1, is used to start the gasoline engine and to engine. A mild hybrid system has the advantage of costing charge the high-voltage batteries. less, but saves less fuel compared to a full hybrid vehicle and usually uses a 42-volt electrical motor and battery package 2. The motor/generator that is connected to the drive wheels, (36-volt batteries, 42-volt charging). An example of this type usually labeled M/G2, is used to propel the vehicle and of hybrid is the General Motors Silverado pickup truck plus the to recharge the high-voltage battery during deceleration Saturn VUE and Chevrolet Malibu. The fuel savings for a mild (regenerative braking). type of hybrid design is about 8% to 15%. Two-motor hybrid electric vehicles are full (strong) hybrids and are capable of propelling the vehicle using electric motor Medium Hybrid power alone for short distances. A medium hybrid uses 144- to 157-volt batteries that provide for engine stop/start, regenerative braking, and power assist. Three-Motor Hybrids Like a mild hybrid, a typical medium hybrid is not capable of Three-motor hybrid electric vehicles are usually two-motor propelling the vehicle from a stop using battery power alone. hybrids that use an additional electric motor to propel the rear Examples of a medium hybrid vehicle include the Honda wheels for all-wheel-drive capability. Hybrid electric vehicles Insight, Civic, and Accord. The fuel economy savings are that use three electric motors include the Toyota Highlander about 20% to 25% for medium hybrid systems. and Lexus RX400h/450h SUVs.

Full Hybrid Features of Hybrids A full hybrid, also called a strong hybrid, uses idle stop The following are the most common features of hybrids that regenerative braking and is able to propel the vehicle using improve fuel economy: the electric motor(s) alone. Each vehicle manufacturer has made its decision on which hybrid type to implement based • Idle stop. The idle stop mode turns off the engine when on its assessment of the market niche for a particular model. the vehicle is stopped. When the brake is released, Examples of a full or strong hybrid include the Ford Escape the engine immediately starts. This ensures that the SUV, Toyota Highlander, Lexus RX400h, Lexus GS450h, vehicle is not using fuel, nor creating CO2 emissions, Toyota Prius, and Toyota Camry. The fuel economy savings when the engine is not required to propel the vehicle. are about 30% to 50% for full hybrid systems. • Regenerative braking. When decelerating, the braking PLUG-IN HYBRID ELECTRIC system captures the energy from the vehicle’s inertia VEHICLES and converts it to electrical energy which is stored in the battery or other device for later use. Regenerative Principles braking helps keep the batteries charged. A plug-in hybrid electric vehicle (PHEV) is a vehicle that is • Power assist. The electric motor provides extra designed to be plugged into an electrical outlet at night to power using electrical current drawn from the battery charge the batteries. By charging the batteries in the vehicle, to assist the internal combustion engine during it can operate using electric power alone (stealth mode) acceleration. This power-assist mode enables the for a longer time, thereby reducing the use of the internal combustion engine (ICE). The less the ICE is operating, the vehicle to use a smaller, more fuel-efficient engine less fuel is consumed and the lower the emissions. Some without giving up vehicle performance. PHEVs offer the driver an option to use the ICE first then • Engine-off drive-electric vehicle mode. Available only switch to EV mode (electric only) later in the trip. This option on HEV that use high voltage batteries over 144- is commonly used where the driver is first traveling on the 158 volts (medium or full hybrids) The electric motor highway and uses the ICE to propel and the vehicle saving propels the vehicle at lower speeds. This mode the energy in the battery to be used when arriving in the city. is often called the motoring mode. Because the internal combustion engine is not being used during Identifying a PHEV acceleration, no fuel is being used and no emissions Many plug-in hybrid electric vehicles are built using a are being released. When the hybrid is in this mode, conventional or a hybrid electric vehicle configuration with it is essentially an electric vehicle. just added battery capacity. As a result, some PHEV may be difficult to pick out such as the plug-in version of the Toyota GAS VS ELECTRIC Prius. The identification of a plug in version of a hybrid electric EFFICIENCIES vehicle includes: • An electric motor can have efficiency (including • different badges (usually stating that it is a plug-in controller) of over 90%, while a gasoline engine only hybrid electric vehicle has efficiency of 35% or less. • an electrical connection door and a door for fuel for the • An ICE does not have the overload capability of an ICE electric motor. That is why the rated power of an SEE FIGURE 7-3. internal combustion engine is usually much higher than required for highway cruising. Operating smoothly at idle speed produces a much lower efficiency than operating at a higher speed. • Maximum torque of an internal combustion engine is reached at intermediate speed and the torque declines as speed increases further. • There is a maximum fuel efficiency point in the speed range for the ICE, and this speed is optimized by many hybrid vehicle manufacturers by using a Figure 7-3 (a) About the only way to tell a plug-in Prius from a transmission that keeps the engine speed within the regular Prius is from the badge on the sides or (b) by the charge port most efficient range. door on the passenger side at the rear. Electric motors offer ideal characteristics for use in a vehicle because of the following factors:

• Constant power over all speed ranges • Constant torque at low speeds needed for acceleration and hill-climbing capability • Constant torque below base speed • Constant power above base speed • Only single gear or fixed gear is needed in the electric motor transmission The operation of the plug-in version is the same as the HEV version of the same vehicle so from a service or maintenance point-of-view, it does not really matter whether it a PHEV or a HEV.

PHEV Battery Capacity The size or capacity of the battery pack used determines how far that the vehicle can travel without using the ICE, commonly called the electric vehicle or EV range. Battery capacity is measured in kilowatt-hours, abbreviated kWh. A kilowatt is a 1,000 watts and is a watt is a volt times an ampere which is a measurement of electrical power. The higher the kWh rating of the battery, the more electrical energy it can store.

• A lower kilowatt-hour (kWh) rated battery weighs less and is less expensive but the range that the vehicle can travel on battery power alone is limited • A higher kWh rating battery means that the battery is capable of propelling the vehicle for a greater distance before the ICE is used. This reduces the fuel used but the larger battery weighs and costs more. Figure 7-4 After the Chevrolet Volt has been charged it uses the electrical power stored in the high-voltage battery to propel the • Therefore, a plug-in vehicle is a compromise between vehicle and provide heating and cooling for 25 to 50 miles (40 to cost and weight of the battery. 80 km). Then the gasoline engine starts and maintains the SOC between 25% and 35%. The gasoline engine cannot fully charge the PHEV Examples high-voltage batteries but rather the vehicle has to be plugged in to provide a higher SOC level. A standard Toyota Prius has a 1.3 kWh battery pack whereas the plug-in version has a larger 4.4 kWh battery allowing electric only travel of about 10 miles before the ICE is used. When the battery pack state-of-charge (SOC) has been Charging a PHEV depleted, the vehicle operates as a standard HEV with the After the battery pack has been discharged propelling the ICE and electric motor both used to propel the vehicle. vehicle, the ICE is used to keep the battery charged enough to propel the vehicle, but it does not fully recharge the battery A Chevrolet Volt has a larger 16 kWh battery pack and, as pack. To fully charge the high-voltage battery pack in a plug-in a result, can travel over 30 miles on electric power alone, hybrid electric vehicle requires that it be plugged into either a without using the ICE until the battery has been discharged to 120-volt or a 240-volt outlet. SEE FIGURE 7-5 about 25% to 35%. At this stage, the ICE is operated to keep the battery pack at a level high enough to keep propelling the vehicle. SEE FIGURE 7-4. TIP to REMEMBER

SEE CHART 7-1 for a comparison of many of the current TURN ON HEAT OR A/C WHILE STILL PHEVs CONNECTED Vehicle Make and Model Batt Type Batt Capacity If charging a plug-in hybrid or an electric vehicle, use BMW i8 Li-ion 11 kWh a smart phone app to access the vehicle to turn on the Chevrolet Volt Li-ion 16 kWh air conditioning or heat 15 minutes before leaving from Cadillac ELR Li-ion 16.5 kWh work. For example, an owner of a Nissan Leaf, who Ford C-Max Energi Li-ion 7.6 kWh works in Phoenix, AZ, uses the phone app to start the Ford Fusion Energi Li-ion 7.6 kWh air conditioning while it is still connected to the charging Honda Accord PHEV Li-ion 6.7 kWh station at work. Then the interior is nice and cool when the Porsche Cayenne PHEV Li-ion 9.4 kWh owner is ready to leave work, even though the vehicle has Porsche Panamera S PHEV Li-ion 9.4 kWh been sitting in the hot sun on a 100 degree day. Because Toyota Prius PHEV Li-ion 4.4 kWh the operation the A/C is occurring while still plugged into VW Golf PHEV Li-ion 8.8 kWh he charging station, the range of the Leaf is not affected and the ride home is done in comfort. The same can be Chart 7-1 The higher the capacity of the HV battery, the further the done to heat the interior in cold weather too. vehicle can travel using electric power only but the longer it takes to be fully charged when plugged into a charger. • Cold temperatures reduce battery efficiency. • Additional electrical power from the batteries is needed to heat the batteries themselves to be able to achieve reasonable performance. • Passenger compartment heating is a concern for an electric vehicle because it requires the use of resistance units or other technology that reduces the range of the vehicle. Batteries perform best when they too are exposed to the same temperature range. Therefore, a proper heating and cooling system must be used to keep the batteries within this fairly narrow temperature range for best performance.

Figure 7-5 (a) The Chevrolet Volt is charged using a standard SAE TIP to REMEMBER 1772 connector using either 110 or 220 volts. (b) After connecting the Batteries like The Same Temperature Range as Humans charging plug, a light on the top of the dash turns green and the dash display shows the estimated time when the high-voltage battery will Batteries work best when they are kept within a temperature be fully charged and the estimated current range using battery power range that is also the most comfortable for humans. Most alone. people are comfortable when the temperature is between 68°F and 78°F (20°C and 26°C). • Below 68°F (20°C), most people want heat. • Above 78°F (26°C), most people want cooling. Batteries perform best when they too are exposed to the same temperature range. Therefore, a proper heating and cooling system must be used to keep the batteries within this fairly narrow temperature range for best performance.

Hot-Weather Concerns Batteries do not function well at high temperatures, and therefore, some type of battery cooling must be added to the vehicle to allow for maximum battery performance. This results in a reduction of vehicle range due to the use of battery power needed just to keep the batteries working properly. ELECTRIC VEHICLES Besides battery concerns, the batteries also have to supply Principles the power needed to keep the interior cool as well as all of the other accessories. These combined electrical loads represent An Electric vehicle (EV) uses a high-voltage battery pack to a huge battery drain and reduce the range of the vehicle. supply electrical energy to an electric motor(s) to propel the vehicle under all driving conditions. Electric vehicles that use Range battery power alone to propel the vehicle are called zero- emission vehicles (ZEVs). The capacity of the battery pack, in How far an electric vehicle can travel on a full battery charge kilowatt-hours (kWh), determines the range of the vehicle and is called its range. The range of an electric vehicle depends then it has to be plugged in to recharge the battery before it on many factors, including: can be driven further. • Battery energy storage capacity Cold-Weather Concerns • Vehicle weight Past models of electric vehicles, such as the General Motors • Outside temperature electric vehicle (EV1) were restricted to locations such as • Terrain (driving in hilly or mountainous areas requires Arizona and southern California that had a warm climate. more energy from the battery) Cold weather is a major disadvantage to the use of electric vehicles for the following reasons: • Use of air conditioning and other electrical devices TIP to REMEMBER The Rule-Of-Thumb Is 3 To help estimate the range of an electric vehicle (EV), multiply the battery capacity in kilowatt-hours (kWh) by three to get a good idea as to the range of the vehicle. For example, a Nissan Leaf has a battery capacity of 24 kWh and when multiplied by 3 equals 72 miles (24 x 3=72).

Vehicle Make Batt Capacity Range and Model in kWh (Miles/km) BMW i3 EV 22 80/130 Nissan Leaf 24 84/135 Ford Focus EV 23 76/122 Figure 7-6 The SAE J 1772 plug is used on most electric and plug-in Chevrolet Spark EV 21 82/132 hybrid electric vehicles and is designed to work with Level 1(110– Fiat 500 EV 24 87/140 120 volt) and Level 2 (220–240 volt) charging. Honda Fit EV 20 82/132 Mercedes B-class EV 31.5 100/160 Because electric vehicles have a relatively short range, Mitsubishi i-MiEV 16 62/100 charging stations must be made available in areas where Smart EV 17 68/109 these vehicles are driven. For example, when the state Tesla 60 208/335 of California mandated the sale of zero-emission vehicles 85 265/426 (ZEV), charging stations were set up in many areas, usually VW Golf EV 25 85/137 in parking lots of businesses and schools. The parking spaces Kia Soul EV 27 90/145 near the charging stations are designated for electric vehicles Chart 7-2 Selected electric vehicles and their battery capacity and only and can be used for free to recharge electric vehicles. published range. CHARGING LEVELS There are three levels of chargers that can be used to charge FREQUENTLY ASKED a plug-in hybrid electric vehicle (PHEV) or electric vehicle QUESTION (EV). The three levels include: What is Range Anxiety? Level 1 Range anxiety is a feeling of many drivers experience Level 1 uses 110- to 120-volt standard electric outlet (20 amp when driving an electric vehicle because they fear of circuit) and is capable of charging a Chevrolet Volt extended running out of electric battery energy before they reach range electric vehicle in 10 hours or more. This long length their destination. This condition is very common but, of time usually means that it I best to allow overnight to according to studies, this feeling lasts about two weeks charge the vehicle so it is ready to go the next morning. The after first getting an electric vehicle. Within those first two advantage is that there is little if any installation cost as most weeks, the driver gets experience regarding how far the houses are equipped with 110-volt outlets and can charge up vehicle can travel on a full charge and knows that their trip to 16 amperes. SEE FIGURE 7-7. can be completed without any issues. Level 2 Level 2 chargers use 220 to 240 volts to charge the same SAE Standard Charger Plug vehicle in about 4 hours. Level 2 chargers can be added to Most electric vehicles and plug-in hybrid electric vehicles, such most houses, making recharging faster (up to 80 amperes) as the Chevrolet Volt and Toyota Prius, use a standard charger when at home, and are the most commonly used charging plug. The standard charger plug meets the specification as stations available at stores and colleges. Adding a level 2 designated by SAE standard J1772 (updated in 2009). SEE charging outlet to the garage or parking location can cost FIGURE 7–6. $2,000 or more depending on the location and the wiring of the house or apartment. SEE FIGURE 7-8.

Level 3 Level 3 charging stations use 440 volts and can charge most electric vehicles to 80% charge in less than 30 minutes. This high-charge rate may be harmful to battery life. Always follow the charging instructions and recommendations as stated in the owner’s manual of the vehicle being charged. Level 3 chargers charge the vehicle using direct current (DC) at a rate up to 125 amperes. Level 3 chargers are often called a DC Quick Charger (DCQC) and can often charge an EV battery to 80% capacity in as little as 30 minutes. A Level 3 charger station can cost $50,000 or more, making this type of charger Figure 7-7 (a) A Chevrolet Volt being charged using the supplied most suitable where facilities will be selling the service of 100 volt charger. (b) Always lay out the entire length of the charging rapidly charging the vehicle. cord before plugging the vehicle into the outlet. If the cord is not kept straight, the current flow can not only create a coil but the flow of There are three designs used for level three chargers current can overheat the wires and in some cases can actually cause including: the insulation to melt. 1. Tesla- The Tesla “superchargers” are level 3 chargers and are free to use by Tesla owners and use a unique to Tesla only connector. Tesla electric vehicles use their own unique plug and supply adaptors if they are going to be connected to a standard SAE J1772 charging station plug or 110 volt electrical outlet. SEE FIGURE 7-9.

Figure 7-9 Tesla uses an unique plug but also supplies adapter so the vehicle owner can plug into a SAE J1772 station or a 220 volt conventional outlet (right) or even to a conventional 110 volt outlet (left)

2. CHAdeMO. CHAdeMO is a Japanese trade name of a quick charging method for level 3 charging using DC electricity at a high rate. “CHAdeMO” is an abbreviation of “CHArge de MOve”, which can be translated to mean “charge for moving.” SEE FIGURE 7-10.

Figure 7-10 A Nissan Leaf electric vehicle charging ports located at Figure 7-8 A Nissan Leaf plugged into a charging station at a college. the front of the vehicle under a hinged door for easy access. 3. SAE Combo Plug- This SAE version under J1772 is 7. Electric vehicles (EV) use a high-voltage battery pack to called the combined charging system (CCS) is used by supply electrical energy to an electric motor(s) to propel VW, BMW and some other EVs since 2012. SEE FIGURE the vehicle under all driving conditions. The capacity of 7-11. the battery pack in kilowatt-hours (kWh) determines the range of the vehicle and then has to be plugged in to recharge the battery before it can be driven further. 8. Most electric vehicles and plug-in hybrid electric vehicles, such as the Chevrolet Volt and Toyota Prius, use a standard charger plug. The standard charger plug meets the specification as designated by SAE standard J1772 . 9. Range anxiety is the fear of running out of battery power before you reach your destination and a place to recharge the HV battery. 10. There are three levels of chargers that can be used to charge a plug-in hybrid electric vehicle (PHEV) or electric vehicle (EV).

DISCUSSION / REVIEW QUESTIONS 1. What are the advantages and disadvantages of mild, Figure 7-11 A Level 3 SAE CCS compatible charging system (CCS) medium, and full hybrid vehicles? station located at the Great Smokey Mountains National park ranger station. There is a charge to use this charger. 2. What are the four modes of operation of a typical hybrid vehicle? 3. What is the difference between a hybrid electric vehicle SUMMARY (HEV) and a plug-in hybrid electric vehicle? 4. What the advantages of using a higher capacity battery in 1. Common features of a many hybrid electric vehicles a PHEV? (HEVs) include: 5. List three operating conditions that would cause an electric • Idle stop vehicle to supply less than normal range. • Regenerative braking 6. What are the three levels of chargers? • Power assist 2. Levels of hybrid include mild, medium and full (strong) CHAPTER QUIZ hybrids 1. Which type of hybrid uses 36 to 42 volts? 3. A plug-in hybrid electric vehicle (PHEV) is a vehicle that is a. Mild hybrid designed to be plugged into an electrical outlet at night to charge the batteries. b. Medium hybrid 4. The size or capacity of the battery pack used determines c. Full hybrid how far that the vehicle can travel without using the ICE, d. Strong hybrid commonly called the electric vehicle or EV range. 5. A lower kilowatt-hour (kWh) rated battery weighs less and 2. Which type of hybrid electric vehicle has idle stop operation? is less expensive but the range that the vehicle can travel a. Strong hybrids only on battery power alone is limited b. Strong, mild, and medium hybrids 6. A higher kWh rating battery means that the battery is c. Mild hybrids only capable of propelling the vehicle for a greater distance before the ICE is used. This reduces the fuel used but the d. Medium hybrids only larger battery weighs and costs more. 3. The storage capacity of HV batteries are rated in______. 9. Which type (level) of charger may be harmful to the a. Volts battery? b. Li-Ion a. Level 1 c. kWh b. Level 2 d. Watts c. Level 3 d. J1772 4. What temperature range do batteries work best? a. 0°F to 32°F (-18°C to 0°C) 10. Why must the charger cord be unreeled and laid out in a straight line when charging an electric or a PHEV? b. 35°F to 65°F (2°C to 18°C) a. To prevent heat buildup in the cable c. 68°F to 78°F (20°C to 26°C) b. To prevent electromagnetic interference d. 90°F to 110°F (32°C to 43°C) c. To allow the current to flow faster to the vehicle 5. How is the high voltage (HV) battery charged in a plug-in d. all of the above hybrid electric vehicle (PHEV)? a. Using the ICE to turn the motor/generator to fully charge the HV battery b. Using an external charging station or electrical outlet c. Can be charged to full capacity by using a special dealer-only high voltage charger. d. Operating the ICE at idle after returning from a trip

6. Why does warm weather decrease the range of an electric vehicle? a. Batteries do not function well at high temperatures b. Batteries have to supply the power needed to keep the interior of the vehicle cool c. Batteries must supply power to help keep the batteries themselves cool d. All of the above

7. The standard charging station plug is usually what SAE standard? a. J1777 b. J1772 c. J1930 d. J1427

8. Which type (level) of charger usually requires that the vehicle be charged overnight? a. Level 1 b. Level 2 c. Level 3 d. J1772