What Is OCPP?
OCPP stands for Open Charge Point Protocol. It is the industry-standard language that EV chargers and back-end systems use to talk to each other. Think of it as the common language between your charger and the software that manages it.
Stekker uses OCPP to send instructions to your charger, telling it exactly how much power to deliver and when. This is what makes smart charging possible.
How Stekker Reaches Your Charger
Stekker does not connect to your charger directly. Instead, it works through your CPO (Charge Point Operator) — the company that manages your charger’s back-end, such as E-Flux, Evesto, or Maxem.
Here is the chain of communication:
- Stekker’s optimization engine calculates the best charging schedule.
- Stekker sends that schedule to your CPO via their integration.
- Your CPO forwards the instructions to your charger using OCPP.
- Your charger adjusts its power output accordingly.
This setup means Stekker works with any OCPP-compatible charger, regardless of brand.
Charging Profiles: Your Power Schedule
The core concept behind smart charging is the charging profile. A charging profile is a timetable of power setpoints — it tells your charger exactly how many kilowatts to deliver at each moment during your session.
For example, a profile might say: deliver 3 kW from 18:00 to 02:00, then ramp up to 11 kW from 02:00 to 06:00. This is sent to the charger as a single OCPP SetChargingProfile command.
Why Your Car Might Not Charge Right Away
If you plug in and nothing seems to happen, don’t worry. Stekker may be intentionally delaying charging because:
- Electricity prices are high right now — Stekker is waiting for a cheaper window. See How Dynamic Pricing Saves You Money for details.
- Your grid connection is under load — other devices or chargers are using the available capacity. Learn more in Understanding Your Grid Connection Limit.
- Solar generation is expected later — Stekker is shifting your session to align with solar production.
Your vehicle will always be ready by the departure time you set. Stekker simply chooses the smartest moment to deliver the energy.
Real-Time Adjustments
Stekker does not just set a plan and walk away. The optimization engine continuously re-evaluates conditions and updates the charging profile when needed. Common triggers for re-optimization include:
- A new vehicle plugs in, requiring power to be redistributed.
- Electricity prices update (intraday market corrections).
- Solar generation differs from the forecast.
- Site power consumption changes unexpectedly.
Each time conditions change, Stekker sends a new charging profile to your charger within seconds.
What Happens If Something Goes Wrong
Stekker is designed with safety in mind. If the connection between Stekker and your charger is interrupted:
- The charger falls back to its own default behavior, which typically means charging at full power. Your vehicle will still charge — just not optimally.
- Once connectivity is restored, Stekker picks up where it left off and sends an updated profile.
- If a session stalls, Stekker detects this and can attempt to restart it by sending a new profile.
In short: the worst case is that your car charges normally without optimization. It will never stop charging because of a Stekker issue.
Stekker Controlling vs. the Charger Deciding
Without Stekker, your charger operates in “dumb” mode: plug in, charge at maximum power until full. Simple, but expensive and potentially harmful to your grid connection.
With Stekker, the charger follows a carefully calculated schedule that considers energy prices, solar generation, grid limits, and your departure time — all at once. The charger itself does not make these decisions; it simply follows the profile Stekker provides.
This is the difference between a charger that delivers power and a system that manages energy.
