EV chargers during the winter: challenges or myths?

Are EV chargers less efficient in the cold? And how do manufacturers ensure reliable operation during the harshest seasons?

We spoke with our Thermal Engineering Specialist, Manuel Côrte-Real, to explore this topic and find out the facts and myths about EV chargers in cold temperatures.

Are EV chargers less efficient in the cold?

 

Cold weather can have some influence on charging speeds, but the effect is often misunderstood. The primary factor lies in the EV battery, which adjusts its charging rate to protect the cells when temperatures are extremely low. When it comes to EV chargers , it is common for chargers to operate reliably at temperatures down to -30 ºC (-22 ºF).


 At i-charging, Manuel explains: “We guarantee the operation of our chargers down to -35 ºC (-31 ºF)”, which means that the charging will be as efficient as if they were operating in mild temperatures such as 15 ºC (59 ºF).

 

How do we do it at i-charging?

 

To guarantee our chargers will function properly and not lose efficiency in the cold, there’s two steps that our Engineering team focuses on. “The first has to do with the heating of the components. The second, which is also related to the cold, is condensation. We have to ensure that condensation doesn’t occur inside the equipment.” 

 

Focus 1 – Heating internal components

Since we guarantee the efficiency of our chargers down to -35 ºC, we need to make sure all components inside the charger can work with these temperatures. However, some of them can have a minimum working temperature higher than that. Manuel explains with an example: “(…) our charger has to work at -35 ºC, so our power supplies, as their minimum temperature is -30 ºC, we always heat them well above their minimum temperature of -30 ºC, to ensure we have a healthy margin.”

 

Focus 2 – Preventing condensation

“We have to ensure that there is no condensation inside the equipment. And condensation can occur when there is a large fluctuation in temperature.” So, to prevent it, we warm up the air inside the charger, because “when we heat the air, the warm air becomes more capable of retaining more water vapour, and the relative humidity drops immediately.”

 

After thorough simulations, a thermal control system ensures resistive heaters activate as needed, maintaining stable internal temperatures even in extreme cold.

 

Myth or fact? 

 

The idea that cold weather “cripples” EV chargers is a myth. While extreme cold can influence battery behaviour and charging rates, charging session failures because of cold temperatures are becoming a thing of the past. At i-charging, our chargers are tested extensively to ensure they keep efficiency at any temperature from -35ºC (-31 ºF) to 50ºC (122 ºF).