What defines a "de‑energized" HV state in an EV?

• A. The HV system is energized but isolated.
• B. Energy storage is discharged but HV circuits are active.
• C. The HV system is isolated and not discharged.
• D. The HV system is isolated per OEM, energy storage discharged, and a voltage check shows no measurable voltage at service points.

Answer: (D)

De-energized means there is no stored energy left in the high-voltage system and no path for energy to reach service points. In EV safety practice, this is achieved by three things working together: isolating the HV system from the vehicle per the OEM procedure, ensuring the energy storage (the battery) is discharged, and verifying with a voltage check that there is no measurable voltage at service points. Isolation stops current from flowing into the HV network, discharging removes the stored energy in the battery and any capacitors, and the voltage check confirms there’s no residual energy that could cause a shock. If any of these steps is missing, energy could still be present. That’s why defining a truly de-energized state includes all three elements: isolation, discharge, and zero-voltage verification at service points.