How does electric car charging work?

Today it is increasingly easy to charge a 100% electric vehicle. It can be done comfortably at home, but also in the office and during various daily activities. In fact, more and more commercial establishments are equipping themselves with charging points to allow customers to charge vehicles during their stops at, for example, a restaurant, gym, supermarket or shopping centre.

Depending on the users, we can first talk about:

• Private access charging points: intended for a limited number of users, in a domestic, apartment block or business environment.

• Public access charging points: located in a private area that provides access to the charging service (e.g. shops, restaurants, and supermarkets).

• Public charging points: located in a public area providing access to the charging service (e.g. in the street, car park or business premises with public areas).

There are different types of charging infrastructure, varying in design and depending on the type of user, the manufacturer, and other characteristics such as the power and space available.

In particular, we have:

• Home Charging Boxes, i.e. devices to be fixed to a wall (but also to a pole, column, etc.). These are generally intended for private use, but not restricted, thanks to the possibility of multiple users. Charging, with these “home points”, is done using alternating current (AC).

• Charging stations in the strict sense of the term, i.e. cylindrical-shaped charging infrastructure - probably the most widespread in Italy - or square-shaped ones, fixed directly to the ground. They generally feature two charging sockets to connect as two alternating current (AC) vehicles.

• Direct Current (DC) charging stations with at least two charging points and integrated cables and connectors. These charging stations also have a column or totem design, but are taller and bulkier than AC and cabinet-based ones.

• The smart lamppost, so called because it integrates the Box home charging point can also lend itself well to use in public areas. It is a solution that combines lighting needs with those of charging battery-powered vehicles.

How is private or public charging infrastructure used? How do you pay for charging electric cars?

The use of charging infrastructure, whether for public or private use, is mainly done with two types of authentication:

• Remotely via an app, which also allows you to locate nearby charging points and manage the various charging operations.

• Via RFID (Radio Frequency Identification) card. This card must be placed on a special plate for user identification and unlocking of the charging point.

In both cases, an electronic payment method for public charging is associated with the user profile. Some public charging points allow the vehicle to be charged directly using a credit or debit card, i.e., without an app or RFID card.

Do you want to know how charging infrastructure works? Find out in the dedicated article.

What is the difference between AC and DC charging infrastructure?

The difference between direct and alternating current lies mainly in the versatility of the latter, due to the greater efficiency of alternators compared to dynamos and the possibility of using transformers for voltage variation. This is why the energy distribution takes place with alternating current (AC).
However, batteries only store direct current (DC), which is why electricity must be fed into the batteries in this way. This is why, with an AC charging station, it is necessary for the energy to be converted to DC by the on-board charger, at a rather low power: although three-phase 22 kW chargers are also available, in most electric cars the power does not exceed 11 kW.
Fast and ultrafast or HPC (high power charging) infrastructure directly feeds 400 or 800 V direct current into the battery, bypassing the internal charger.