Most EV charger “faults” reported by end users are not product failures. They are tripped protection, supply problems, vehicle settings, network issues or physical damage. A smaller share are genuine component failures. Good suppliers help distributors tell the two apart quickly, with clear fault codes, a triage guide and fast replacement when the fault really is the charger.
The Most Common Faults
| Symptom | Likely causes | First checks |
|---|---|---|
| Charger will not power on | Tripped breaker or RCD, loose supply connection, worn outlet | Reset protection, test the outlet or supply, inspect the plug for heat marks |
| Residual current or earth fault | Moisture in connector or plug, vehicle-side fault, missing or poor earth | Dry and inspect connectors, try another vehicle, check earthing |
| Charging starts then stops | Overheating, supply voltage drop, vehicle schedule, load balancing limit | Check vehicle settings, measure voltage under load, check ambient temperature |
| Vehicle shows “not ready” or no communication | Connector not fully seated, damaged control pilot pin, latch problem | Reseat connector, inspect pins and latch, test with another vehicle |
| Slow charging | Current set low, vehicle limit, single-phase supply, heat derating | Check current setting and vehicle on-board charger rating |
| Hot plug or outlet | Worn outlet, loose terminal, extension cord, undersized wiring | Stop use, have an electrician inspect the outlet and wiring |
| App or network offline | Wi-Fi signal, router change, firmware mismatch | Check signal at the charger, re-pair, update firmware |
| Physical damage | Cable driven over, dropped connector, broken holster | Stop use, replace damaged parts |
Faults That Come From the Site
Worn household outlets are a leading cause of hot plugs on portable chargers. A portable charger draws high current for hours, which exposes loose or worn contacts. Extension cords make this worse; our portable EV charger buying guide explains why they should not be used.
Undersized circuits and nuisance RCD trips are common on older installations. The charger’s built-in 6 mA DC detection and the type of upstream RCD must match; see RCD protection for EV chargers.
Weather plays a part too: water in an unprotected connector, ice in a latch, or a charger derating in direct sun. See cold-weather charging and hot-climate charging.
Faults That Point to the Product
- The same error on several vehicles and several known-good supplies.
- Relay or contactor failure: no output despite a normal handshake, or a “welded relay” error.
- Display, LED or button failures.
- Temperature sensor errors at normal ambient temperatures.
- A cluster of identical faults in one production batch.
These should go straight to the supplier with serial numbers, fault codes and photos.
What a Supplier Should Provide
- A fault code table in the manual, with plain-language causes and actions for each code or LED pattern.
- A triage guide for distributors covering the checks above, so support staff can resolve site issues by phone.
- Remote diagnostics for smart chargers: logs, firmware version and event history.
- Fast replacement of confirmed faulty units or parts from local stock; see spare parts and the RMA process.
- Failure analysis with root cause and corrective action for every returned unit or batch pattern.
- Firmware updates that fix known issues without a site visit.
Preventing Faults at the Source
- Specify protections clearly: RCD or DC fault detection, over-temperature, over- and under-voltage, earth monitoring.
- Choose an enclosure rating suited to the site; see IP ratings.
- Require end-of-line testing records and a pre-shipment inspection; see pre-shipment inspection and AQL sampling.
- Plan periodic checks for commercial sites; see the commercial maintenance checklist.
How EVDANCE Supports Distributors
EVDANCE chargers are tested at the end of the line before shipment, and every partner has a dedicated account engineer for fault reports and analysis. Products carry a 3-year standard warranty. See our distributor program.
Frequently Asked Questions
Why does my EV charger keep tripping the breaker?
Common causes are an undersized circuit, a breaker that is worn or of the wrong type, moisture in a connector, or a fault on the vehicle side. Test with another vehicle and have an electrician check the circuit.
Why does the plug of my portable charger get hot?
Usually because of a worn or loose outlet, or an extension cord. Stop using it and have the outlet inspected; the charger’s plug should also be checked for damage.
How do I know whether the charger or the car is at fault?
Try the charger on another vehicle and the vehicle on another charger. A fault that follows the charger points to the charger.
Can firmware fix charging faults?
Some, such as compatibility or communication issues. Hardware damage and failed components need a part or unit replacement.
Related Reading
- OEM and Private-Label EV Chargers: A Complete Guide for Brands
- EV Charger Warranty and After-Sales Terms: A Distributor’s Checklist
- RCD Protection for EV Chargers: Type A, Type B and 6 mA DC Detection Explained
- Commercial EV Charger Maintenance Checklist
Key Takeaways
- Many reported faults come from the supply, the vehicle, the network or physical damage, not the charger.
- Worn outlets and extension cords are a leading cause of hot plugs on portable chargers.
- Suppliers should provide fault code tables, triage guides, remote diagnostics and fast replacement.
- Track faults by serial number and batch so real product issues are found and fixed.
Sources & Standards
- IEC 61851-1 — Electric vehicle conductive charging system, Part 1: General requirements
- IEC 62752 — In-cable control and protection device for mode 2 charging
- IEC 62955 — Residual direct current detecting device for mode 3 charging