As is now evident, the automotive world is in continuous and rapid evolution, with the electron undisputed protagonist of this change. Putting aside autonomous driving and infotainment for a moment, in fact, we are experiencing what is commonly referred to as the “electric transition”. Virtually all car manufacturers now include fully or partially electrified vehicles in their portfolio.
But if among the fully electric cars we do not have major differences in terms of operation, the partially electrified cars, better known as hybrids, are instead divided into three different categories: Mild Hybrid, Full Hybrid and Plug-in Hybrid. Now, we know that for NON-experts these terms can still create a lot of confusion, and that is precisely why we decided to make this short guide. Within this article you will find explained in a simple way the three technologies and the characteristics that differentiate them from each other.
Before starting, however, it is necessary to make a premise. To develop this content, we used Hyundai’s collaboration; Very careful and avant-garde company in the process of electrification of its range. Attentive to the point that, probably, we are talking about the brand with the widest range of electrified vehicles: Mild Hybrid, Full Hybrid, Plug-in, 100% electric and even hydrogen.
MILD HYBRID
Well, without going any further, I would say to start with our explanation. Let’s go in ascending order by importance of the electric system and then start with Mild Hybrid cars. Also known by the acronym MHEV, Mild Hybrid Electric Vehicle, they are currently the most numerous category but, probably, also the most controversial and the one around which more doubts have arisen. But don’t be scared, it’s actually much simpler than it seems.
First of all, the basic concept is that we are facing cars that can NEVER travel driven only by the electric motor. These are in fact endothermic cars to which a small electric motor and a battery with its electrical system have been added that can be 12V, 24V or 48V, depending on the power of the system itself (in the case of Hyundai we always talk about 48V). This electric motor provides, at best, 10-12 kW of power and about 150Nm of torque.
Fine, but when does the electric motor activate? The electron engine is always activated in combination with the combustion engine in all those situations in which the latter needs help to reduce the effort and optimize consumption and emissions. Specifically, we are talking about the moment of ignition of the car, at the start, in the maneuvering phases and when you need a little more inspiration, perhaps to overtake.
The only situation in which the electrical system works autonomously is in the sailing phases, that is, when the accelerator is released and the car proceeds by inertia. In an endothermic car the engine would remain on, here instead it turns off maintaining the engine brake function, and the electrical system takes over to keep all the systems active and to eliminate the lag due to the ignition of the thermal engine when we start to press the accelerator again. In essence, therefore, the electric motor is able to optimize performance and consumption in all those phases in which the thermal engine is less efficient.
This electric propulsion system is obviously supported by an additional battery compared to the classic one of the car, usually contained in size and with a capacity of about 0.5 kWh. This battery is always and only automatically recharged during deceleration and braking. It is therefore not possible to attach the car to charging stations or sockets.
What are the main advantages of a mild hybrid system? Surely among the pros of this technology we have its adaptability. Adding these components to an existing platform is a fairly simple operation and does not involve a significant increase in weight for the cars in which it is used. But we cannot forget the reduction of consumption and emissions, which is equally important. All this combined with a low price, especially if we consider the Full-Hybrid alternatives and even more Plug-in Hybrid. Within the Hyundai range, among the Mild Hybrid proposals we find for example i20, i30 (here our road test), Bayon, Kona and Tucson, all with a 48V hybrid system and with costs slightly higher than endothermic alternatives.