With the arrival of cold weather, most electric car users have noticed that the speed of charging in fast chargers is noticeably slower compared to summer temperatures. But why is that?
The answer lies in physics and chemistry
The battery is as important to an electric car as the engine is to a petrol or diesel car. Keeping it healthy and maximizing its life is a priority for both car manufacturers and users.
Battery charging and discharging is a chemical process that is directly affected by temperature and environmental conditions. In winter, the chemical reaction in the battery takes place more slowly, which means that the battery cannot accept current as quickly as in warmer temperatures.
In cold weather, the charging speed is limited by the car itself
The main reason for the decrease in charging speed is not the charger, but the temperature of the battery itself. The electric car’s control system detects the temperature of the battery and the surrounding environment and slows down charging to prevent cold stress that damages the battery. During the charging process, the temperature of the battery rises, and with it the charging speed.
Therefore, it is recommended to drive for at least 10-15 minutes before charging, so that by the time you start charging, the temperature of the battery has risen, charging is “healthier” for the battery and the speed is higher. If you make a comparison from everyday life, you should not put a hypothermic person in a hot sauna, but gradually warm them up.
In addition to the battery temperature, the following factors also affect the charging speed:
- Charger capacity: How much energy the charger can provide to the vehicle (e.g. 50 kW, 150 kW, 180 kW, etc.).
- Car capacity: Each car and battery system has its own specific charging speed. It is important to keep in mind that even different versions of the same model from the same car manufacturer can differ from each other.
- Battery capacity: In other words, how much energy is in the car battery at the start of charging. Charging speed is usually fastest when the battery is empty and slower when the battery is full.
Why does battery temperature affect charging speed?
As we mentioned at the beginning of the article, the battery stores and releases energy through chemical reactions. As the temperature drops, these reactions become less efficient. For example:
- In lithium-ion batteries (which are common in electric cars): At low temperature, the viscosity of the electrolyte increases, which makes it difficult for lithium ions to move between the anode and the cathode. The result is a slower loading speed.
- Internal resistance increases with cold: Higher resistance means more heat is generated during charging and the system limits the current to prevent overheating or damage to the battery.
How to make the most of fast charging in winter?
- Drive before charging: If the battery is too cold, it is recommended not to charge immediately after parking for a long time, when the car has been standing idle. The car battery heats up when driving, so it is wise to drive the car before going to the fast charger to warm up the battery for charging.
- Use preheating: Many electric cars have the option to preheat the battery and the interior before starting the journey, if the car is connected to the charger. This reduces energy consumption while driving and promotes faster charging.
- Plan Your Loads Consciously: In winter, it makes sense to charge after a long drive when the battery is already warm. In summer, on the other hand, it is good to start charging before a long drive so that the battery does not overheat.
You will find more useful tips on how to drive an electric car in cold weather and slippery conditions from here.
This is Enefit On the energy wisdom blog with the published story. Read the full article from here.
The Energiatarkus blog is a website created by Enefit, where we share up-to-date information about what is happening in the energy world and help make better energy decisions. Using today’s tricks, we create a smarter tomorrow.
Source: online.le.ee
