What Diagnostics Means
Diagnostics is the set of tools and data used to identify, explain, and resolve issues in an EV charger or charging network. Diagnostics combines status monitoring, fault codes, logs, and measurements to answer three questions: what happened, why it happened, and what to do next.
Why Diagnostics Matter
Good diagnostics reduce downtime and service cost while improving user experience. They help operators and installers:
– Detect faults early and prevent repeat failures
– Restore service faster with fewer on-site visits
– Differentiate hardware, installation, grid, and software problems
– Support warranty decisions with evidence (timestamps, measurements, event history)
– Improve fleet uptime for depots and destination sites
What Diagnostics Typically Includes
Diagnostics data usually falls into these categories:
Real-Time Status Monitoring
– Online/offline status and last heartbeat
– Charger availability (operative, occupied, out of service)
– Connector state (plugged, charging, finished, faulted)
– Session state (authorized, charging, suspended, ended)
Fault Codes and Alarms
– Internal fault codes (power module, contactor, RCD, meter, comms)
– Safety alarms (overcurrent, overheating, insulation faults)
– External alarms (grid undervoltage/overvoltage, phase loss)
– Repeated or persistent faults vs one-time events
Logs and Event History
– Time-stamped events (boot, reset, firmware update, errors)
– OCPP message history and rejected commands
– User actions: RFID auth attempts, start/stop triggers
– Maintenance actions: service mode, parameter changes
Measurements and Telemetry
– Voltage/current per phase (AC), frequency, power factor
– Power (kW), energy (kWh), meter readings
– Temperature readings, fan speeds, internal humidity (if available)
– Network metrics: RSSI, latency, packet loss (cellular/Wi-Fi)
Remote Diagnostics vs On-Site Diagnostics
Most charging operations use both:
Remote diagnostics (via CPMS / device twin)
– Fast triage and pattern detection
– Remote resets, parameter tweaks, firmware rollback
– Evidence gathering before dispatching a technician
On-site diagnostics (installer/service visit)
– Electrical checks: grounding, RCD behavior, insulation resistance
– Physical checks: cable glands, water ingress, connector wear
– Network checks: router, firewall, signal in garages
– Verification that civil works and mounting meet requirements
Common Root Causes Diagnostics Helps Separate
– Grid and installation issues: phase loss, voltage drop, neutral problems, poor earthing
– Connectivity issues: weak cellular, blocked ports, unstable Wi-Fi
– Vehicle interaction issues: plug locking, pilot signal errors, EV-side limits
– Hardware faults: contactors, meters, power supply, thermal failures
– Software/configuration issues: wrong limits, bad tariff rules, CPMS misconfig
– User/access issues: RFID not provisioned, roaming auth failures
Best Practices
– Standardize fault code mapping and severity (info / warning / critical)
– Keep logs time-synced (NTP) for reliable incident timelines
– Track repeats: “same fault on same unit” is a different problem than random faults
– Combine diagnostics with workflows: auto-ticketing and technician checklists
– Use clear acceptance tests after fixes (functional + safety + comms)
Common Pitfalls
– Too many alerts without severity rules (alarm fatigue)
– No event history → “it’s offline” with no clue why
– Poor metadata (wrong site name, wrong serial, missing installer info)
– Not separating installation faults from hardware faults → warranty disputes
– Ignoring connectivity planning, especially in underground parking
Related Terms for Internal Linking
– Charger diagnostics
– Device twins
– Remote monitoring
– Intrusion detection
– Secure update pipeline
– OTA firmware updates
– Uptime
– Service level agreement (SLA)