Heatwave: If you own an electric car, stop doing this immediately

While the thermometer is panicking for this weekend in June, motorists driving on electricity are preparing to face a technical challenge. Charging your electric car in direct sunlight exposes the battery to major heat stress, with direct consequences on the wallet and waiting time.

The general public often associates electric vehicle battery failures with freezing winter temperatures. Yet summer heatwaves are proving just as daunting for today’s mobility technologies.

The lithium-ion storage cells which equip the majority of the French vehicle fleet have a very strict thermal comfort zone, located between 20 °C and 30 °C.

As soon as the external temperature crosses the 35 °C mark, energy management is becoming a high-risk calculation.

Automatic restriction of charging on the motorway

The first trap awaits drivers at rest areas during major departures. To protect components from destructive overheating, the vehicle’s on-board computer and fast charging station communicate to activate electronic security.

This automatic mechanism will limit the charging power, sometimes by more than half of its usual capacity. Concrete result: the waiting time to recover 80% of autonomy can easily double, considerably extending the duration of journeys.

A sudden drop in battery life

Filling your electron tank under a blazing sun also causes a vicious energy cycle. To maintain the battery at an acceptable temperature during the charging effort, the vehicle’s liquid cooling system must run at full throttle.

This internal air conditioning dedicated to the cells consumes a significant amount of energy. Consequently, the actual autonomy displayed on the dashboard drops before even getting back on the road, part of the injected kilowatt hours having been immediately consumed to cool the system.

The risks of premature aging of cells

Beyond simply wasting time at the terminal, plugging in your vehicle in extreme heat accelerates the chemical degradation of internal components. The accumulation of ambient heat and the heat generated by the high voltage electrical flow creates intense heat stress.

In the long term, repeating this operation at midday irreversibly reduces the maximum battery capacity, directly impacting the resale value of the vehicle on the second-hand market.

Summer best practices

To get around these physical constraints without damaging your equipment, simple rules are essential. Experts recommend favoring charging sessions during cool hours, either early in the morning or late in the evening, when the concrete slab of the stations no longer accumulates heat.

If the obligation to recharge occurs during the day, it is strongly recommended to choose shaded or underground charging points, and to prefer slow terminals at moderate power to limit the rise in temperature of the circuit.