Electrical practice. Electric car and hot weather: it works less well…

Some impacts are quite similar to those caused by extreme cold. But there are also some peculiarities that are interesting to know. Indeed, lithium-ion batteries do not like extreme temperatures.

The ideal operating temperature is around 25° C and the range of use given by manufacturers varies between – 25 and + 45° C. Temperature is one of the factors that has the greatest influence on battery life, especially when it is used at more than 45°C.


In winter, and especially in summer, recharging in a temperate place prevents overheating of the charging station and the battery.  Photo Zeplug

In winter, and especially in summer, recharging in a temperate place prevents overheating of the charging station and the battery. Photo Zeplug

The importance of cooling

Batteries heat up quickly when charged at high power and driven at high speed. Hence the importance of a high-performance cooling system so as not to notice any loss of power, whether when driving or when recharging.

The liquid cooling system is preferable to forced ventilation. An advantage for Audi, Hyundai, Jaguar, Kia, Porsche or Tesla compared to Renault or Nissan… Regarding liquid cooling, it protects both the performance and the health of the battery cells.

Consequences of heat

During episodes of high heat, the operation of the car may be altered; power losses may be felt when accelerating and the user may also find that the battery does not charge as quickly as expected. In question, the cooling system which will slow down, or even block recharging while the cells cool down.

Insofar as you want to charge your vehicle outside, the good reflex would be to avoid the hours between 12 p.m. and 3 p.m., when the sun’s radiation is strongest.


Avoid charging during the hottest hours, when solar radiation is at its peak.  Ford picture

Avoid charging during the hottest hours, when solar radiation is at its peak. Ford picture

Overheating of charging stations

Charging stations therefore suffer from being often exposed to direct sunlight. The optimum operating threshold (+ 45° C) is sometimes reached, or even exceeded, and the charging power may be altered.

Following a sharp rise in temperature, the fast charging station (direct current DC) can go into safety mode to avoid overheating or only deliver a few kW of power.

To avoid this problem, charging networks like Fastned equip their terminals by protecting them with a roof covered with solar panels which avoids excessive heat.


The charging rate automatically reduces as the battery approaches the overheating point.  In extreme heat, it takes longer to recharge.  Photo Zephyr

The charging rate automatically reduces as the battery approaches the overheating point. In extreme heat, it takes longer to recharge. Photo Zephyr

Prevent loss of autonomy

In the event of a heat wave, the use of air conditioning can also affect the range of the 100% electric car. In order to preserve the comfort of the occupants, it is better to program the pre-conditioning of the passenger compartment during the recharging period; this avoids draining the battery and losing up to 20 to 30 km of autonomy.

To avoid charging problems, choose a station in the shade or underground. Finally, in order to keep as much autonomy as possible, use the Eco mode which will limit performance but will allow you to go a little further.