What is meant by stored energy in the HV system, and how do you manage it?

• A. Stored energy dissipates instantly after power removal.
• B. Energy is stored only in the wiring.
• C. Capacitors and energy storage can retain voltage after power is removed; manage by following OEM discharge procedures and verify energy is zero before work.
• D. There is no stored energy in EV HV systems.

Answer: (C)

Stored energy in an HV system is the energy kept in capacitors and other energy storage components that can keep the system at a hazardous voltage even after power is removed. This means voltage can remain present for a short time, so simply turning off power does not guarantee it’s safe to work.

To manage it, you must follow the OEM discharge procedures, which are designed to safely remove that stored energy. This usually involves isolating the HV system, using the prescribed discharge path, and then verifying with a properly rated high-voltage meter that the energy has been reduced to zero before any work begins. Remember that discharge times vary by design, so never assume it’s safe just because power is off.