Not charging

The most common cause is usually a poor connection between the charger and the vehicle or power source (poor plug contact or fuse/circuit breaker trip).

The following troubleshooting steps are provided, from easiest to most difficult (each step: symptom → possible cause → solution → precautions):

1) Symptom: The charger has no indicator light or the indicator light is completely off → Possible causes: No power at the power outlet / Tripped circuit breaker / Damaged charger power cord → Solutions: Try a known working outlet, check the circuit breaker, measure the outlet voltage with a multimeter, or replace the power cord → Precautions: Ensure the outlet is properly grounded, and avoid touching live terminals with bare hands during measurement; if you are not familiar with electrical work, please consult a professional.

2) Symptom: Charger indicator light is on, but the vehicle is not receiving power or is receiving power very slowly → Possible causes: Loose connection between the charger output and the vehicle (poor plug contact) or oxidation of the plug/socket → Solution: Unplug and plug the charger several times after disconnecting the power, clean the plug and socket (with alcohol or contact cleaner), and tighten the connection; replace the damaged plug if necessary → Precautions: Always disconnect all power before cleaning and operation to avoid short circuits with metal tools.

3) Symptom: The charger stops working after a short while, or the fuse/circuit breaker is triggered → Possible causes: The fuse at the vehicle or charger end has blown, the vehicle circuit breaker has tripped, or the short-circuit protection has activated → Solution: Check and replace the fuse, reset the circuit breaker; check for short circuit points in the wiring (worn wires, bare wire contacts) → Precautions: Use the same specification and model when replacing fuses, avoid arbitrarily increasing the rated value; continuous triggering indicates a deeper short circuit, requiring professional inspection.

4) Symptom: Charger displays an abnormal code or charging current is significantly lower than the nominal value → Possible causes: Voltage mismatch (charger output voltage/current does not match battery pack specifications) or charger enters current-limiting mode → Solution: Confirm that the charger’s nameplate output (V/A) matches the battery pack’s rated voltage/capacity; if mismatched, select a charger with appropriate specifications → Precautions: Different battery chemistry and the number of cells in series determine the voltage. Verify the actual battery pack’s nominal voltage and do not force charging with high voltage.

5) Symptom: Unable to charge in low-temperature environments or charger displays “charging prohibited” → Possible cause: Low-temperature protection (charger or battery management system (BMS) is enabled) preventing charging → Solution: Move the battery/vehicle to a warm environment or use temperature-controlled charging, wait for the temperature to rise, and try again; consult the BMS/charger manual for temperature thresholds → Precautions: Forcing charging at low temperatures will damage the battery; avoid directly heating the battery surface with external heating pads (may be uneven).

6) Symptom: Charger indicator shows charging is connected, but charging time is shorter than expected or suddenly stops → Possible cause: BMS protection (overvoltage/undervoltage/temperature/current abnormality) actively disconnects the charging path → Solution: Use diagnostic equipment to read BMS fault codes or check dashboard prompts; correct the root cause triggering the protection (e.g., individual cell voltage imbalance, overheating) → Precautions: Consult with the vehicle/battery manufacturer or an experienced repair technician. BMS resets should be done with caution to avoid masking potential battery problems.

7) Symptom: The charger overheats, emits an unusual odor, or makes a burning sound during operation. → Possible causes: Aging or overloaded internal components, fan failure, or poor heat dissipation. → Solution: Disconnect the power and stop using the charger; do not attempt to charge it again. Send it for professional repair or replace the charger. → Precautions: Continued use may cause a fire or further damage. If you notice an unusual odor, immediately disconnect the power.

8) Symptom: The multimeter shows no power output or unstable output under no-load conditions. → Possible causes: Internal charger malfunction (damaged transformer, rectifier, or control board) or software/firmware issues. → Solution: Contact the manufacturer or a qualified repair shop for inspection; if under warranty, seek after-sales repair or replacement. → Precautions: Disassembling the charger yourself carries a risk of electric shock and further damage. Unless you have power supply repair experience, do not open the casing.

When should the charger be replaced?

• The charger still fails to output power normally after checking all external factors (socket, fuse, wiring harness, BMS); or it repeatedly overheats, smokes, or smells of burning.
• The charger has been used for many years (typically more than 5–8 years, or the number of charging cycles is close to/exceeds the manufacturer’s recommended lifespan) and is showing signs of performance degradation or frequent failures;
• It cannot be repaired or the repair cost is close to or exceeds the cost of purchasing a new machine; or the manufacturer has stopped providing spare parts/support.

Three criteria for selecting a charger: 1) Specification matching and intelligent communication: The output voltage/current must match the vehicle’s battery pack. Prioritize chargers that support BMS communication (CAN/RS485, etc.) or have voltage/temperature compensation for coordinated protection and balancing. 2) Protection and certification: Ensure the charger has over-temperature, short-circuit, over-current, reverse connection, and low/high temperature protection functions; check for CE, UL, or locally recognized safety certifications and a reliable warranty. 3) Heat dissipation and build quality: Choose chargers with good heat dissipation design (fan or aluminum casing), waterproof and dustproof ratings suitable for the operating environment (e.g., higher IP rating for outdoor garage environments), and from reputable brands or suppliers with after-sales support.