How a Charging Session Begins
Starting a charging session with Stekker is straightforward: plug in your vehicle and present your card. Behind the scenes, a sophisticated process kicks off — from authentication to smart scheduling — but as a driver, all you need to do is tap and go.
Here is what happens step by step, and how you can manage your cards and preferences.
RFID Cards: Your Charging Key
An RFID card is a small physical card (or key fob) with a unique identifier. When you hold it against a charge point, the charger reads the card and sends the identifier to Stekker for authentication.
Each card is linked to your Stekker account. This connection is what allows Stekker to:
- Verify that you are authorized to charge at this location
- Associate the session with the correct vehicle and account
- Apply the right charging schedule and optimization settings
Card Assignment Options
Cards in Stekker can be configured in several ways to match your organization’s needs:
Per vehicle
Link a card to a specific vehicle. When this card starts a session, Stekker automatically knows the vehicle’s battery size, charging speed, and driver preferences. This is the most common setup.
Per site
Assign a card to a specific site. Useful for shared vehicles or locations where multiple drivers use the same charge points.
Organization-wide
Some cards work across all sites in your organization. This is convenient for fleet drivers who charge at multiple locations.
Priority Levels
Each card can be assigned a priority level:
- High priority — the vehicle gets preferential treatment in the charging queue. If capacity is limited, high-priority vehicles are charged first. Use this for vehicles that need to be ready at specific times or for essential fleet vehicles.
- Normal priority — the default level. Vehicles are scheduled based on available capacity and departure time.
Priority only matters when there is more demand than available power. When capacity is abundant, all vehicles charge at their maximum rate regardless of priority.
What Happens After Authentication
When you present your card at a charge point, the following sequence takes place in seconds:
- The charge point reads your card and sends a StartTransaction request via OCPP
- Stekker receives the request and authenticates your card
- A new charging session is created in the system
- The optimizer is triggered — it calculates the best charging schedule based on your departure time, vehicle needs, grid capacity, solar forecast, and other active sessions
- The charge point receives its power setpoint and charging begins
From this moment, Stekker continuously adjusts the charging power as conditions change — new vehicles arrive, solar production shifts, or grid signals come in.
Mobile App Authentication
Not everyone carries an RFID card. The Stekker mobile app offers an alternative way to start a session. You can scan a QR code at the charge point to authenticate and begin charging directly from your phone.
The app also lets you monitor active sessions, see charging progress, and review your history.
Managing Cards in Your Dashboard
Site administrators can manage all cards from the Stekker dashboard:
- Add new cards and link them to vehicles or accounts
- Set priority levels
- Assign cards to specific sites or make them organization-wide
- Deactivate lost or stolen cards
Common Questions
What if my card is not recognized?
If the charge point rejects your card, check that the card is registered in your Stekker dashboard and assigned to the correct site. If it was recently added, there may be a short delay before it propagates to the charge point. Contact your site administrator or Stekker support if the issue persists.
Can I use my card at a different location?
That depends on how your card is configured. Organization-wide cards work at any site within your organization. Site-specific cards only work at their assigned location. Your administrator can adjust this in the dashboard.
Want to learn more about how Stekker optimizes once a session starts? See how your site configuration drives optimization and how grid flexibility adds value.
