When you buy an electric car for the first time, you are faced with charging management. At first it can be a bit scary but then, after a little experience, everything becomes very simple and immediate. As the charging infrastructure evolves, there are more and more high-power direct current (HPC) charging stations on the roads that allow you to fill up with energy quickly.
Plenitude + Be Charge, for example, now has over 17,000 charging points installed in Italy. Among these there are several columns that can deliver up to 300 kW powers.
Especially when you are still a beginner, you often wonder why if you connect to a 300 kW column you don’t really reach these powers. It may happen, in fact, that even if the car is connected to a similar charging point, the car does not go beyond, for example, 100 kW or even less.
Problem with the column? Breakdown of the machine? None of that.
The battery “commands”
To better understand why these powers cannot be achieved, we need to take a step back and better understand how an electric car battery works. Simplifying as much as possible to better understand the concept, in direct current columns, it is the battery that “commands”.
Each accumulator has precise operating specifications that are communicated by the car manufacturer. If a battery can refuel at a maximum of 100 kW, even if you connect to a column that allows you to deliver more power, you will not be able to exceed this maximum threshold.
Therefore, it is absolutely normal that from a 300 kW charging point you do not go beyond 100 kW if this is the limit of the accumulator. In addition, another very important element must also be remembered, and that is the “charging curve“.
The battery, in fact, cannot always replenish at full power. There are a few elements that affect the amount of energy it can accept, such as state of charge (SoC) and temperature. As a rule, the maximum charging power can be reached when the battery is very discharged. Power that will then progressively decrease as you get closer to full charge. Therefore, even if the battery is able to reach 200 kW of power, if HPC charging starts at 60%, the power that can be reached will be much lower than the maximum power.
Optimize charging
Precisely because it is the battery that “commands” during direct current recharging, it is possible, however, to follow practices that allow you to be able to supply energy by making the most of the potential of the accumulator.
Batteries are the most important element of an electric car and in order to perform in the best way, not only during charging, they must operate within a precise temperature range. Precisely for this reason, they have an air conditioning system that allows you to keep them at an optimal temperature.
Speaking strictly of charging, if the battery cells have reached the correct temperature, it is possible to make the most of the DC columns, obviously within the technical limits provided.
Especially in the cold seasons, however, when the batteries work at low temperatures, the BMS, i.e. the software that manages the operation of the accumulators, can also heavily limit the power accepted during charging.
Therefore, in cold periods, before recharging at the HPC columns, it is essential to preheat the batteries through the special option of the car, or to travel a little way so that the cells can be brought to an optimal temperature. These are small tricks to know in order to properly use your electric car.
If you’re going on a long journey, the optimal strategy is not to go too far beyond 80% of the charge. In fact, once this threshold is exceeded, the power often drops significantly, greatly lengthening the dwell times. It is not for nothing that car manufacturers, when talking about fast charging the batteries of their electric cars, provide charging times up to the threshold of 80% and no more.
When buying an electric car, it is very important to understand the performance of your model’s battery in all contexts. At that point, you can set the best strategy to be able to make the most of HPC charging. However, first it is essential to know what we have told and that is how the battery works and its behavior during direct current energy supplies.
And alternating current?
So far, we’ve talked about high-power DC charging. What about the low-power AC one? Here the situation is different. From these columns, it is not the battery that controls but the on-board charger, normally 7 or 11 kW. Models that allow you to go to 22 kW are rare. Therefore, there are usually no problems in reaching the maximum possible power if the column delivers the correct quality of energy.
Article by Hd Motori
Are you looking for an electric charging point? Search on the Charging Network map
