It is completely normal for the cooling fan of the Avatr 07 (as with nearly all modern electric and plug-in hybrid vehicles) to operate while charging at home AC power at a high capacity of 11 kW to 12.5 kW. This is an essential safety feature for the following main reasons:
1. The On-Board Charger (OBC) generates high heat
When charging at home (AC), electricity flows from the charger into the vehicle as alternating current (AC), whereas the car’s battery stores only direct current (DC).
Therefore, the vehicle uses a device called the On-Board Charger (OBC), hidden inside the car, to convert AC to DC.
Converting high power at 11 to 12.5 kW is quite substantial for AC power, causing the OBC module and high-power electronic circuits to heat up quickly. The system then activates the cooling fan to blow across the OBC radiator/cooling assembly.
2. Battery Thermal Management System (BMS & Battery Thermal Management)
During charging, chemical reactions inside the lithium-ion battery produce heat.
The Avatr 07’s Battery Management System (BMS) monitors and maintains the battery temperature within a safe range, typically not exceeding 30-35°C.
If the temperature rises, the system activates the coolant pump and radiator fan at the front of the vehicle (and sometimes the battery system’s air conditioner compressor) to dissipate heat from the battery.
3. Climate conditions in Thailand
Thailand’s hot ambient temperature, especially when charging outdoors or in poorly ventilated garages, makes natural vehicle cooling difficult. Thus, the fan works harder and spins faster to expel heat promptly.
Recommendations & things to observe
It is normal and not a cause for concern. The loud fan noise (sometimes accompanied by compressor sound) indicates the safety system is functioning as designed.
Do not block or cover the front grille or undercarriage vents to allow proper airflow for effective cooling.
If the fan does not operate at all during high-capacity charging, this may indicate a problem (which could cause the OBC to shut down due to overheating or slow charging).
Therefore, hearing the fan run loudly at 12.5 kW charging means the Avatr 07’s cooling system is working properly and normally!