Introduction to Charge Station
Within the electric mobility management system the Charge Station, also referred to as EVSE (Electric Vehicle Supply Equipment), EV (Electric Vehicle) charger, or charging point, is the physical system that supplies the electrical power needed to charge an EV's battery.
Hardware and features
Charge Stations are mounted on the ground or on a wall. Depending on the model they come with one or more charging cables attached, are fitted with several sockets for connecting the EV's cable, or they have a combination of both cables and sockets. Charge Stations typically feature an RFID card scanner and a QR code. The latter allows drivers to authorise and start charge sessions with an app like GreenFlux's Charge Assist. Some types of Charge Stations feature a card payment terminal and/or a display with extra functionality.
The electrical outlets or sockets of the Charge Station are called connectors. Connectors comply with a variety of standards to support the many different types of charge cables EVs come equipped with.
Below you see a typical Charge Station consisting of two EVSEs: EVSE 1 on the left has one connector, EVSE 2 on the right has two:
Given the spatial limitations of a Charge Station's surroundings and the limited length of cables, commonly no more than two vehicles charge simultaneously at a single Charge Station.
Difference between AC and DC
AC (Alternate Current) Charge Stations are currently the most common type of Charge Station found across European cities. The majority of these AC Charge Stations have a charging speed of 22 kW or less.
DC (Direct Current) Charge Stations, ranging from less than 100 kW up to 400 kW, are usually commissioned at high turnover locations like motorway rest stops where faster charging is preferable.
DC Charge Stations that can provide 80% of battery charge in less than 30 minutes are referred to as DC fast chargers.
An EV battery, like all batteries, can only store power as DC. For that purpose, EVs have an inbuilt converter that transfers the power received from an AC Charge Station to the DC power type needed to be stored in the battery. With DC Charge Stations this larger converter is built into the Charge Station itself, which allows the EV's converter to be sidestepped and results in faster charging.
Accessibility
Across the EV industry, a distinction is made between public Charge Stations, semi-public Charge Stations and private Charge Stations (the latter are often home chargers although there may be cases where they are not).
Public Charge Station
A public Charge Station is open for use to anyone with a valid Charge Card (RFID card) issued by an E-Mobility Service Provider (EMSP). Common standards, like the OCPI (Open Charge Point Interface) protocol, have been developed to accommodate automated roaming between charging networks so that EV drivers can charge at point-of-need at any Charge Station Operator's (CPO) Charge Station in any country. This is referred to as interoperability across vendors.
Public Charge Stations are usually found on-street, on parking lots, at forecourts on highways, or at public facilities like hospitals, shopping centres and gyms.
Semi-public Charge Station
Semi-public Charge Stations are restricted to be used by a certain group of drivers, for example residents of an apartment complex, at workplaces, business parks or in fleet charging setups.
Private Charge Station
Private Charge Stations are typically matched to drivers belonging to a single household and are not accessible to the general public.
Charge Stations and the GreenFlux backend
For a physical Charge Station to be able to 'communicate' with GreenFlux - meaning that the GreenFlux system can receive messages from and send messages to the Charge Station - a virtual Charge Station has to be created in the GreenFlux system. The physical Charge Station has to be connected to the GreenFlux backend via a public or private endpoint. It also needs to be connected to the internet, either via Ethernet/LAN cable, a wireless connection or a SIM card, so it can send live information about its activity (think driver authorisations, charging activity, error notifications etc.) to GreenFlux. Some data will be shared with the Charge Assist app or other GreenFlux API powered apps, for example to indicate if a public Charge Location is currently available or to show a driver the progress of their charging session in real time.