Why you may struggle to charge your electric car if it’s hot

We know that electric cars do not like the cold very much, but very high temperatures can also affect their proper functioning. That’s why.

Electric cars are a bit like humans: whether it’s too hot or too cold affects their overall performance. The cold causes electric cars to increase their consumption and to recharge more slowly on direct current (DC) terminals. This is also the case during the phases of heat wave, but it is a little less known. One thing is certain: if you have more difficulty charging your electric vehicle when the outside temperatures are very high, this is not abnormal.

It’s not always the fault of the car if the charging power is low. Charging stations also suffer from being often exposed to direct sunlight.

Not all cars are created equal in the heat

Batteries are particularly sensitive to weather conditions. For optimum operation, anodes and cathodes need to remain within a given temperature range. This range of temperatures depends on the type of battery used and is specific to each model, but overall they should be below 40°C.

Depending on the cooling means put in place by the manufacturers to cool the battery, the vehicles will therefore be more or less affected by high temperatures. A good part of electric models that have recently arrived on the market have more efficient cooling than in the past. The liquid cooling system is now preferred, and even more specifically for large capacity batteries. However, some vehicles of older design, such as the Renault Zoe or the Nissan Leafhave much less efficient cooling systems.

Zoe in charge. // Source: Pixabay @Stivabc

Highways and fast charging can quickly give fever to an electric car that does not have a suitable cooling system. This was particularly what Challenges was able to experiment with the Leaf in 2019. If we combine poor cooling for certain uses with high temperatures, we obtain more complex situations to manage. Sometimes you have to wait a while before starting the recharge, so that the battery returns to acceptable temperatures. These strategic choices, and often cost reductions, are made by manufacturers at the expense of buyers, who know little or nothing about these technical aspects of the operation of an electric vehicle.

In short, if it’s very cold or very hot, you sometimes have to be a little patient to recharge. If the battery is not at the correct temperature, charging power can be limited by the on-board system in order to preserve the battery. It is also necessary to know how to be vigilant at the slightest signs of possible overheating. In the same way as with a thermal model, a break when the dashboard indicates an anomaly can be judicious.

Terminals also suffer from exposure to the sun

During the summer period, it is not uncommon to encounter charging stations broken down, even more than the rest of the year. With many requests during the big departures on vacation and exposure to direct sunlight, these two ingredients combined put the electronic components to the test. Terminals can also overheat and operate in degraded mode.

fastned understood this well by placing its terminals under shading awnings, which are also covered with solar panels. Total Energies also installs its fast charging stations under awnings. It is time that other manufacturers and charging network operators are also considering this solution. It’s also useful both when it’s raining and when it’s bright and sunny, and you can no longer read the displays on the control screen.

Fastned station on highway. // Source: Raphaelle Baut for Numerama

A charging station is only profitable if it is functional and used. So there is still progress to be made.

Battery technologies are evolving rapidly, as are terminal technologies. While waiting for technologies that will be less sensitive to the weather, we must, alas, know how to make some concessions.