Chapter 7 Flashcards
Which of the following best describes the category of batteries that tends to be used in most current electric vehicle (EV) powertrains?
A. Lead-acid
B. Nickel cadmium (Ni-cad)
C. Alkaline
D. Lithium-ion (li-on)
D. Lithium Ion
Technician A says that UCs will sustain up to a million charge and discharge cycles. Technician B says that UCs can hold large amounts of electrical energy but discharge it more slowly than most types of batteries. Who is correct?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A nor B
A. tech A only
While a li-ion battery is being discharged, which of the following is true?
A. Lithium ions move from the anode to the cathode.
B. Lithium ions move from the cathode to the anode.
C. Lithium ions are discharged into the ground circuit.
D. A thermal runaway is likely.
A. Lithium ions move from the anode to the cathode
Technician A says that although the voltage is high in an EV, there is usually insufficient available current to cause a serious injury. Technician B says that the EESS in an EV can output high-voltage exceeding 900 volts. Who is correct?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A nor B
B. Tech b only
What frequency ac is used on the North American grid?
A. 600 hertz
B. 400 hertz
C. 60 hertz
D. 50 hertz
C. 60 Hz
Which of the following li-ion cell technologies has proven to be the most thermally stable?
A. NMC
B. NCA
C. LTO
D. LFP
D. LFP
How many NMC cells are required to produce a pack voltage of at least 80 volts-dc?
A. 1
B. 8
C. 12
D. 22
D. 22
Technician A says that battery strings are arranged in parallel to form a bank. Technician B says that li-ion packs are arranged in series to form a string. Who is correct?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A nor B
B. Tech b only
Technician A says that battery cells are arranged in parallel to increase string current. Technician B says that battery banks are connected in series to form a string. Who is correct?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A nor B
A. tech a only
Technician A says that EVs use multiple battery banks in a series to increase the nominal operating voltage. Technician B says that using multiple battery banks in parallel increases the electrical energy storage capacity. Who is correct?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A nor B
Which of the following is in the correct sequence, listing the unit with the lowest potential listed first?
A. String, bank, pack, cell
B. Cell, pack, string, bank
C. Bank, cell, pack, string
D. Cell, string, pack, bank
B. Cell, pack, string, bank
What is the height of a cylindrical battery cell with an IEC code of 21700?
A. 21 mm
B. 2.1 inches
C. 70 mm
D. 7.0 inches
C. 70mm
If a technician places DMM dc voltage probes across the terminals of an isolated battery cell, which of the following accurately describes the meter reading?
A. Float voltage (FV)
B. Open circuit voltage (OCV)
C. Cut-off voltage (COV)
D. Terminal voltage (TV)
D. Terminal voltage
When a cell state-of-charge (SoC) decreases, which of the following will also decrease?
A. Open circuit voltage (OCV)
B. Energy density
C. E-rate
D. All are correct.
D. All
Which li-ion cell chemistry does Tesla use in their 2021 Model 3 standard range automobile?
A. LTO
B. NMC
C. LCO
D. NCA
