charger outlet in car not working

The most common cause is poor plug contact or a tripped fuse/circuit breaker on the vehicle/charger side. Start by checking the externally visible and easily accessible parts.

Below is an 8-step troubleshooting checklist arranged from easiest to most difficult, with each step following the order: Phenomenon → Possible Causes → Solutions → Precautions.

1) First, confirm whether there is power from the external power source.

• Symptom: When the charger is plugged in, there are no indicator lights on the charger, and the vehicle still does not charge.
• Possible cause: The wall socket/extension cord/public charging station is not powered or is not connected to power.
• Solution: Use a known working electrical appliance (desk lamp/electric drill) or a multimeter to check if there is AC power in the socket; try a different socket or test directly over a short distance without using an extension cord.
• Precautions: Exercise caution when operating high voltage. If you are not familiar with AC voltage measurement, please ask someone knowledgeable about electricity for help. Do not operate with wet hands or in a damp environment.

2) Check the external extension cable/power cord and the charger power plug.

• Symptoms: The charger has a weak indicator light, works intermittently, or has no response at all.
• Possible causes: poor quality extension cable, poor contact, or oxidation of contacts.
• Solution: Plug the charger directly into a wall socket without an extension cord, or try a known working power cord.
• Precautions: Avoid using damaged or ungrounded extension cords; if you must use an extension cord for an extended period of time, choose a thicker wire with the appropriate current rating.

3) Check the physical contact between the charger and the vehicle’s socket (poor plug/socket contact).

• Symptoms: Loose contact after plugging into the charging port, intermittent charging current, or overheating at the contact point.
• Possible causes: Oxidation, bending, or blockage of plug pins, or loose or poor contact of the internal spring of the socket.
• Solution: After disconnecting the power, clean the plug and socket (wipe with alcohol swabs, use a rust remover brush), straighten any bent pins, and reinsert them tightly; replace the socket or plug if necessary.
• Precautions: Always disconnect the power before cleaning; do not use sandpaper to vigorously polish the metal contacts, as this will damage the plating.

4) Check the fuses/circuit breakers on the vehicle and charger side.

• Symptom: The charger indicator light is off or the charging current is zero, indicating a previous sudden current change or short circuit.
• Possible causes: The main fuse in the vehicle body, the built-in fuse in the charger, or the AC side circuit breaker has blown/tripped.
• Solution: Consult the vehicle manual to locate the relevant fuse and check if it is blown; replace it with a fuse of the same specification or reset the circuit breaker. If the fuse blows frequently, the cause of the short circuit must be identified and repaired.
• Precautions: When replacing a fuse, you must use the same model and specifications as the original. If you are unsure, please consult a professional technician to avoid damaging the circuit.

5) Check the indicator lights or fault codes of the vehicle/external charger (charger self-test/communication problem).

• Symptom: The charger has an indicator light, but it flashes abnormally or displays an error code; the vehicle’s display screen shows “Cannot charge” or “Under protection”.
• Possible causes: charger self-test failed, internal electronic module malfunction, or communication failure with vehicle BMS.
• Solution: Refer to the charger manual for the meaning of the indicator lights/codes, power off and restart the charger and vehicle, and reconnect and unplug the communication cable; if the code indicates a hardware failure, contact after-sales service or replace the charger.
• Precautions: Save screenshots or records of error codes for easy after-sales diagnosis; ensure there are no flammable materials nearby before powering off and restarting.

6) Check if the voltage matches (voltage mismatch)

• Symptoms: The charger can be powered on but cannot charge, or the charger works but the current is extremely low.
• Possible causes: The charger’s output voltage/current is not compatible with the battery pack’s rated voltage (e.g., using a 36V charger for a 48V battery), or the setting mode is incorrect (mixing lead-acid/lithium battery modes).
• Solution: Use a multimeter or charger parameter table to confirm that the charger output voltage matches the battery’s nominal voltage; check if the charger settings match the battery type, and replace with a charger of the correct voltage/type if necessary.
• Precautions: Do not force a high-voltage battery to use a low-voltage charger, as this may result in the battery not charging or damage to the device; conversely, using a higher-voltage charger to charge a low-voltage battery may be dangerous, so avoid attempting it.

7) Check the Battery Management System (BMS) and Low Temperature Protection (BMS Protection / Low Temperature Protection)

• Symptom: The charger fails to start charging, the vehicle displays “BMS protection” or only starts charging when the temperature rises.
• Possible causes: The BMS detects that the battery is too low/too high, the individual cell voltage is unbalanced, it is over-discharged, or there is a communication abnormality, and therefore prohibits charging; some chargers/battery packs have low temperature charging protection and automatically stop charging when the temperature is low.
• Solutions: Check the BMS/dashboard error codes and measure the battery pack temperature and individual cell voltages. If it is low temperature protection, move the battery to a warmer environment or use gentle heating (do not use open flames or high-power heaters directly). If it is a BMS error or individual cell imbalance, perform balancing charging according to the manufacturer’s instructions or contact a professional repair service.
• Precautions: Do not attempt to short-circuit the BMS to bypass protection; forced charging under low temperature conditions may damage the battery or cause safety risks.

8) Inspect internal wiring harnesses, relays, or chargers for internal faults (deep inspection).

• Symptoms: After all the above checks, the device still does not charge, or the charger makes abnormal noises, overheats, or has a burning smell.
• Possible causes: broken internal plating, poor grounding, stuck relay/contactor, or faulty internal components of the charger (such as damaged rectifier or filter capacitor).
• Solution: Have a qualified technician use professional instruments (ammeter, oscilloscope) to check the wiring harness, resistors, relay working status and charger internal circuitry. If necessary, replace the faulty module or the entire unit.
• Precautions: Repairs involving high voltage/high current must be performed with the power off and by qualified personnel; attempting internal repairs yourself carries high risks and may result in personal injury or void the warranty.

When should the charger be replaced?

• After multiple repairs, the same faults recurred, and the repair costs were close to or exceeded the cost of a new machine.
• The charger fails to provide power, internal modules burn out, or there is an irreparable communication failure (such as severe incompatibility with the BMS).
• The charger is severely aged, has poor heat dissipation, frequently overheats, or the manufacturer has stopped production and cannot provide spare parts or warranty support.

Three recommended criteria for choosing a charger: 1) Electrical compatibility: The output voltage and maximum charging current must be compatible with the battery pack’s nominal voltage, capacity, and BMS; the interface/plug must be compatible with the vehicle. 2) Safety and protection functions: Support communication with the BMS (if the battery is lithium-ion), have overvoltage/undervoltage, overcurrent, short circuit, overtemperature, and low-temperature protection, and have relevant certifications (CE/UL, etc.) and a reasonable protection rating (IP). 3) Brand/warranty and after-sales service: Choose a reputable brand with timely after-sales response and warranty service, and ensure that parts and technical support can be obtained locally.