CAR Electric & Hybrid Vehicle Processing 2 — Questions and Answers
Question 1: Before cutting into a high-voltage battery pack housing during EV dismantling, the technician must confirm the pack is fully de-energized by measuring voltage between the service disconnect and pack terminals. What reading indicates it is safe to proceed?
- Less than 60 volts DC (Correct answer)
- Less than 120 volts AC
- Less than 12 volts DC
- Zero volts on every cell module individually
Correct answer: Less than 60 volts DC
OSHA and OEM guidelines define 60 V DC as the threshold below which a high-voltage system is considered de-energized and safe for unprotected contact.
Question 2: Which federal regulation governs the transportation of damaged or defective lithium-ion EV battery packs classified as hazardous materials?
- 49 CFR Part 173.185 (Correct answer)
- 40 CFR Part 261
- 29 CFR 1910.303
- 40 CFR Part 279
Correct answer: 49 CFR Part 173.185
49 CFR 173.185 sets DOT packaging, labeling, and documentation requirements for lithium batteries shipped as hazardous materials.
Question 3: A plug-in hybrid's high-voltage system uses orange-colored cables. What is the primary reason orange is the industry-standard color for these conductors?
- To provide immediate visual warning of high-voltage potential (Correct answer)
- To meet SAE J1772 charging port color codes
- To comply with NEC Article 690 wiring standards
- To differentiate coolant lines from power cables
Correct answer: To provide immediate visual warning of high-voltage potential
ISO 6469-3 adopted orange as the universal high-voltage cable identifier so first responders and technicians can instantly recognize lethal conductors.
Question 4: When storing a partially depleted EV battery pack awaiting recycling, what state of charge (SOC) range do most recyclers target to minimize thermal runaway risk?
- 15–25% (Correct answer)
- 50–60%
- 80–90%
- 0% (fully discharged)
Correct answer: 15–25%
Most OEM and recycler protocols recommend storing Li-ion packs at 15–25% SOC, which reduces stored energy while avoiding damaging deep discharge.
Question 5: An automotive recycler removes a nickel-metal hydride (NiMH) battery from a hybrid and must dispose of it. Which program is specifically designed to handle end-of-life NiMH hybrid batteries in the US?
- Call2Recycle (Correct answer)
- Earth911 drop-off network
- EPA Universal Waste Program
- DOE Battery Lifecycle Initiative
Correct answer: Call2Recycle
Call2Recycle operates the primary US take-back and recycling network specifically for rechargeable batteries including NiMH hybrid packs.
Question 6: Which tool is essential for verifying that a Toyota Prius Gen-3 high-voltage system is fully isolated before removing the battery service plug?
- A calibrated high-voltage multimeter rated CAT III 1000V (Correct answer)
- A standard 12V test light
- An analog ohmmeter
- An insulation resistance tester set to 9V
Correct answer: A calibrated high-voltage multimeter rated CAT III 1000V
Only a CAT III 1000V-rated digital multimeter can safely measure the lethal voltages present in hybrid/EV systems without risk of arc flash or instrument failure.
Question 7: During the thermal runaway of a lithium iron phosphate (LFP) battery cell, which gas is primarily released that creates an asphyxiation hazard in enclosed spaces?
- Carbon monoxide and carbon dioxide (Correct answer)
- Hydrogen fluoride only
- Hydrogen sulfide
- Nitrogen dioxide
Correct answer: Carbon monoxide and carbon dioxide
LFP thermal runaway produces significant CO and CO₂ along with trace toxic gases, making CO/CO₂ the primary asphyxiation concern in enclosed recycling facilities.
CAR Electric & Hybrid Vehicle Processing 2
Before cutting into a high-voltage battery pack housing during EV dismantling, the technician must confirm the pack is fully de-energized by measuring voltage between the service disconnect and pack terminals.
What reading indicates it is safe to proceed?