Golf cart not charging

The most common cause is poor contact of the charging plug or wiring/a blown fuse, resulting in the charger not having a stable power supply or being unable to deliver current to the battery pack.

Here is an 8-step troubleshooting checklist, ordered from easiest to most difficult. Each step lists: Symptom → Possible Cause → Solution → Precautions.

Step 1 — Charger and wall socket/power indicator light

• Symptom → The charger has no indicator light, does not light up, or is completely unresponsive.
• Possible causes → Charger not powered: wall socket, circuit breaker tripped, extension cord/plug loose, or household fuse blown.
• Solution → Try another known working outlet; check the household circuit breaker/switch; plug in the short power cord directly; confirm that the charger’s power switch (if applicable) is on.
• Precautions → Exercise caution when operating with electricity and avoid humid environments; do not use damaged extension cords or inferior sockets.

Step 2 — Connecting the charger to the vehicle (poor plug contact)

• Symptoms → Intermittent charging interruptions, fluctuating charging current, heat at the contact points, or slight flashing/hissing sounds.
• Possible causes → Poor contact due to oxidation, bending, loosening, or damage to the waterproof ring of the charging gun/plug pins.
• Solution → After power off, check and clean the contact surfaces of the plug and socket (with a cloth or special contact cleaner), straighten bent pins, re-insert and secure; replace the damaged plug or socket assembly if necessary.
• Precautions → Ensure the charger is disconnected before operation; do not excessively sand the metal contacts (this will damage the plating); after cleaning, confirm that the seals are intact to prevent water ingress.

Step 3 — Vehicle/Charger Side Fuses and Circuit Breakers

• Symptoms → The charger indicates abnormality or no output at all; there is a “fault” indicator light or charging is interrupted.
• Possible causes → A blown fuse in the charging circuit or vehicle circuit, a tripped thermal disconnector, or a blown fuse in the terminal block.
• Solution → Check the circuit diagram for the location, inspect and replace the fuse with one of the same specifications; reset or replace the triggered circuit breaker/thermal protection component.
• Precautions → Only use fuses with matching specifications; do not use high-capacity fuses as substitutes. If the fuse blows again in a short period of time, the cause of the short circuit needs to be found; do not replace it multiple times directly.

Step 4 — Measure the charger output (confirm that the charger has an output)

• Symptom → The charger light is on but there is no current output, and the voltage reading is abnormal or zero.
• Possible causes → Internal charger malfunction (rectifier, switching power supply or output relay failure), internal fuse or temperature control shutdown.
• Solution → Use a multimeter to measure the open-circuit voltage at the charger’s output terminal (compare with the manufacturer’s specifications); if there is no output or the output is unstable, send the charger for repair or replacement.
• Precautions → Strictly follow electrical safety regulations during measurement; if you are not familiar with live measurement, please have it handled by a professional.

Step 5 — The total voltage of the battery pack does not match the voltage of the individual cells (voltage mismatch)

• Symptoms: The charger displays an error code, charging stops quickly, and the voltage of some individual components is significantly lower or higher than normal.
• Possible causes → Battery pack imbalance (some cells have fallen off or there is a large voltage difference), mixing of batteries of different capacities or specifications, or damage to individual cells.
• Solution → Use a multimeter or battery tester to check the overall voltage of the battery pack and the voltage of each individual cell; for slight imbalances, perform equalization charging as recommended by the manufacturer; if there are obviously damaged or severely degraded batteries, replace the problematic batteries and consider replacing the entire pack in pairs.
• Precautions → When measuring individual battery cells, ensure reliable contact to avoid short circuits; when replacing batteries, try to use batteries of the same model and production batch to ensure consistency.

Step 6 — BMS Protection / Low Temperature Protection

• Phenomenon → The charger does not start or flashes briefly after being connected; the charging current is very small; charging is rejected at low temperatures.
• Possible causes → The battery management system (BMS) detects excessively low or high voltage, excessively low temperature, overcurrent, or communication abnormalities and enters protection mode; many BMSs will disable charging at low temperatures (e.g., below 0°C) to protect the battery.
• Troubleshooting → Check if the BMS has any fault codes (some BMS systems can read error codes or display them on the vehicle’s display); raise the battery temperature to a safe range (e.g., move it to a warm environment or cover it with a blanket), reset the BMS (follow the instructions), or troubleshoot the BMS communication/sensor lines.
• Precautions → Do not force the battery to charge at high current under low temperature conditions; if the BMS frequently triggers the protection, consider sending it for professional repair or replacing the BMS.

Step 7 — Vehicle body wiring, grounding, and terminal resistance (loose wiring/corrosion/poor grounding)

• Phenomenon → Voltage reaches the target during charging but the actual current is insufficient; localized heating occurs during charging; mileage is far lower than expected.
• Possible causes: Poor contact of the main negative terminal, positive terminal, or grounding wire; insufficient cross-sectional area of ​​the wiring leading to voltage drop; terminal corrosion increasing contact resistance.
• Solution → After power off, tighten all main connection terminals, remove oxide layer, and replace excessively thin or damaged wires with the manufacturer’s recommended specifications if necessary; measure the terminal voltage difference during charging to confirm voltage drop.
• Precautions → When fixing the terminals, use the recommended torque; when replacing cables, use appropriate wire diameter and terminal material to avoid temporary splicing.

Step 8 — Battery capacity degradation/short circuit in a single cell (battery aging)

• Phenomenon → The charging display shows “full”, but the actual battery life is short. After charging, the voltage drops rapidly or there is a significant increase in internal resistance.
• Possible causes → Battery aging, sulfation (lead-acid), increased internal resistance, short circuit in individual cells, or insufficient capacity.
• Solution → Perform a capacity test or load test to confirm battery health; if the capacity drops significantly or the internal resistance of individual cells varies greatly, replace the battery or the entire battery pack as needed to ensure consistency.
• Precautions → Batteries are consumables. Continuing to use them after they have aged will pose safety and performance risks. When replacing batteries, prioritize batteries of the same specifications and type and match them with other batteries.

When should the charger be replaced?

• When the charger is confirmed to have no output or unstable output after measurement, and the repair cost is close to or exceeds the replacement cost;
• The charger may have internal water leakage, severe overheating, a cracked casing, or damaged electrical components (especially the high-voltage part).
• The charger frequently reports malfunctions, the indicator lights are abnormal, or the charger is old (e.g., used for more than 8-10 years, poorly maintained), and the manufacturer has stopped maintaining it or spare parts are scarce.

Three criteria for choosing a charger (recommended)

1. Voltage and current matching and battery chemistry compatibility: Ensure the charger’s nominal voltage matches the car’s battery pack (e.g., 36V/48V). The recommended charging current is 10–20% of the battery’s rated capacity (C/10–C/5), which is a common safe range.
2. Compatible with BMS and possessing necessary protection/communication: preferably supporting temperature compensation, low temperature/over temperature protection, overcharge/short circuit/reverse connection protection, and ideally able to communicate with the vehicle BMS (CAN, signal line, or fault indication) for easy interlocking and fault diagnosis.
3. Reliability and safety certifications, after-sales service: Choose brands with safety certifications such as CE/UL, good heat dissipation design (IP rating and fan/heatsink), manufacturer warranty, and spare parts supply. If necessary, choose a smart charger with status display or Bluetooth/APP for easy viewing of fault codes and charging curves.