DC charging is a system-level process. The charger, vehicle, connector, PLC communication, insulation monitoring, contactor control, and backend logic all need to move through the same sequence. When a handshake fails, engineers should isolate the phase where the failure occurs instead of guessing.
Start with the communication layer. Confirm whether the vehicle uses DIN 70121, ISO 15118-2, or ISO 15118-20, then check whether the charger supports the same route. For Plug & Charge projects, also confirm certificate handling, TLS configuration, and backend support.
Useful checks include cable rating detection, PLC startup, protocol version agreement, cable check, insulation monitoring, pre-charge voltage, EV current/voltage limits, and backend authorization logic. A repeatable test matrix with different EV models is the best way to reduce field surprises.
