Connected Charging Stations

Plug&Charge is a dedicated electric vehicle charging technology that only functions with connected stations, considered smart. These stations can communicate with the vehicles that connect to them and access certain owner data. This communication process is transparent for the vehicle’s designated user, especially since they would have previously shared the necessary information for secure payment of their charges. User authentication occurs automatically as soon as they plug into the station, triggering charging and billing in a transparent manner. The invoice should be available immediately after charging, either on the car manufacturer’s app or on a dedicated app to be determined.

For the driver, the charging experience is thus more seamless and straightforward when they need to recharge outside their home, such as at public charging stations or at their workplace.

Bear in mind that Europe advocates for the production of renewable energies, which cannot be stored conventionally. Doing so would require creating large batteries and deploying them across the territory, a reality that would contradict the EU’s goals. This is the issue addressed by “vehicle-to-grid” (V2G). Its contribution will be significant because a car spends, on average, 90% of its time parked, hence potentially plugged in. V2G allows cars to act as storage units for this “green” energy and for the charging stations, which need to be bidirectional, to function as converters capable of feeding this energy back into the grid.

During peak consumption times, the highly demanded electrical grid sometimes cannot meet everyone’s needs. The principle is to use the batteries of parked electric vehicles to store energy produced during low electric consumption periods. This electric energy can then be injected back into the grid when demand rises and the vehicle is not in use. By 2025, the year when V2G-compatible vehicles are expected to be on the market, this system will be useful in situations of electrical grid tension and/or severe weather conditions. Island territories are a prime example of the usefulness of this innovation. Particularly vulnerable to major climatic events, electric cars and their batteries would serve as backup generators while waiting for the restoration of electrical networks. It should be noted that several studies have confirmed that V2G does not degrade the lifespan of batteries.

Operators, including Bouygues Telecom, have international “roaming” agreements. These agreements not only support charging station manufacturers with an international presence but also allow already installed charging stations that are not yet connected to be connected without having to work with multiple connectivity providers. Thanks to the connectivity of charging stations, users have access to a seamless experience regardless of the country where they recharge their vehicle. Indeed, for a manufacturer, not only does the international deployment of connected charging stations become easier:

• It will be possible to perform maintenance actions remotely in case of problems with the station as well as to contact customer service directly (the station manager can restart it if a cable gets stuck, for example).
• They will also be able to update their station remotely.

And users also find their benefits:

• They will be able to access all the information concerning their charge from a single application,
• In the long run, they will no longer need to use several RFID cards,
• It will be possible to view the availability and operating status of stations before stopping at one,
• They will spend less time at the station,
• They will benefit from simplified expense reports: a connected station is capable of determining the exact consumption of a vehicle, and of creating a specific invoice – or even transmitting it directly to the company for a monthly reimbursement.

Several manufacturers are also working on creating a payment terminal integrated into the station: the user will only have to make a bank imprint before connecting and will be debited once the charge is finished.

These three innovative devices – which are or will be deployed, cannot function without the cellular networks that support them. All usually use 4G technology, knowing that LTE-M can also be suitable. In this respect, the market is also concerned by innovations that facilitate communication between objects and management systems. Note: the 2G and 3G networks will soon no longer be available. We talked about it in this article: 2G and 3G take their bow.

To connect charging stations, two technologies are generally used: 4G and LTE-M. Generally, the choice between these two networks depends on the use and constraints.

Use case for 4G: Ideal for global coverage without latency

The 4G network has had extended functionalities for a few years already, on cellular IoT to meet market demand, particularly in terms of connection speeds. 4G connects so-called IoT objects requiring high-speed networks to ensure both the reception or transmission of significant volumes of data, in real-time or continuously, as well as those requiring voice. One of the main advantages of using this technology is also the rapid global coverage because 4G already has roaming agreements in a very large number of countries, where agreements linked to LTE-M are still being deployed given that this technology is newer.

Using 4G therefore allows you to benefit from high speed and low latency: two essential characteristics for billing consumption, but also for ensuring connectivity of stations.

Use case for LTE-M: Ideal for connecting stations located in underground or semi-underground areas and saving energy

LTE-M (Long-Term Evolution for Machines) is a low-energy technology and less expensive than 4G modems. It has two sleep modes that save battery life:

• The “semi-awake” mode (eDRX) where it no longer communicates but receives information,
• The “hibernation” mode (PSM) where it no longer communicates and no longer receives information.

The use of LTE-M is also recommended for real-time communications because of its low latency, which guarantees a minimum time between sending large amounts of information and receiving them.

LTE-M allows sending back information from the station during a recharge, in particular the measurement of the amount of electricity consumed by the vehicle, a valuable indication to know what volume of recharge has been done and to be able to bill the customer.

The stations are connected to the cellular network via Bouygues Telecom antennas. The communication is then encrypted to the core of the network. The information then passes through a VPN before reaching the customer’s server.