OCPP vs OCPI: Smart Charging, CSMS, and the Role of SCSPs in EV Fleet Operations

As electric vehicles become the backbone of fleet electrification, operators face a fundamental challenge: how to keep charging predictable, cost-efficient, and future-proof. The solution lies in three complementary standards and roles:

• OCPP (Open Charge Point Protocol): the standard for charger-to-CSMS communication
  
  
• OCPI (Open Charge Point Interface): the protocol for roaming, services, and smart charging profiles
  
  
• SCSP (Smart Charging Service Provider): the entity delivering grid intelligence and flexibility signals
  
  

At the center sits the CSMS (Central Management System), the platform that turns these signals into reliable charging operations.

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OCPP: Charger Control at the Edge

OCPP is the global backbone for charger communication. It lets the CSMS control and monitor stations, regardless of vendor.

• OCPP 1.6-J: still widely deployed, enabling basic smart charging
  
  
• OCPP 2.0.1 and 2.1: advanced security, ISO 15118 support, V2X, and better DER integration
  
  

With OCPP, a CSMS can:

• Collect and normalize telemetry
  
  
• Apply charging profiles and load balancing
  
  
• Handle updates, diagnostics, and remote management
  
  

It ensures every charger, old or new, behaves consistently under one management layer.

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OCPI: Services, Interoperability, and Smart Charging Profiles

Where OCPP handles the charger itself, OCPI manages the external world: roaming, tariffs, tokens, CDRs, and now smart charging profiles.

In the latest OCPI 2.2 and 2.3.0 specifications, ChargingProfiles allow external services to send load instructions directly to the CSMS. This makes it possible for fleets to connect not only to mobility services (eMSPs) but also to energy flexibility platforms and SCSPs.

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SCSP: Smart Charging Service Providers

An SCSP is the entity that brings grid and market intelligence into charging operations. Examples include energy aggregators, DSOs, or flexibility platforms.

Through OCPI, an SCSP can:

1. Send a charging profile to a fleet operator’s CSMS
   
   
2. The CSMS validates it against depot priorities
   
   
3. OCPP commands are sent to chargers
   
   
4. Chargers adjust charging in real time
   
   

The result:

• Fleets reduce costs by charging when energy is cheapest
  
  
• Depots support grid stability by reducing peaks
  
  
• Operations stay reliable thanks to CSMS mediation
  
  

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The CSMS as the Integration Hub

The Central Management System is where all protocols and roles converge.

• Southbound (OCPP): device control and charger monitoring
  
  
• Northbound (OCPI): interoperability with roaming networks, eMSPs, and SCSPs
  
  
• Core: logic that balances operational needs with external signals
  
  

The CSMS is what makes smart charging predictable at scale.

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How Bia Works: Two Customer Pathways

At Bia, we make this complexity simple. Depending on customer needs, we deliver smart charging via two main models:

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1. Bia as CSMS with Smart Charging

For fleets and depots that do not yet have a CSMS or want a unified platform, Bia provides the full CSMS solution, including:

• OCPP device control
  
  
• Charger anomaly detection and self-healing automations to increase charger performance/health.
  
  
• Smart charging co-optimisation algorithms
  
  
• Dynamic load management
  
  
• Integration with OCPI roaming and energy services
  
  

This is the all-in-one approach: one dashboard, one charging strategy, all chargers in sync.

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2. Bia as SCSP via OCPI

Some customers already have a CSMS in place but lack smart charging capabilities. In this case, Bia acts as an SCSP.

• The existing CSMS stays in place
  
  
• Bia connects via OCPI
  
  
• Smart charging profiles are delivered into the customer’s CSMS
  
  
• The CSMS translates them into OCPP commands for chargers
  
  
• Bia still secures other integrations like fleet management systems, meter sensors, solar PV, or ERP.
  
  

This means customers can keep their current infrastructure while upgrading instantly to advanced smart charging.

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Why This Matters for EV Fleets

• Scalability: Add chargers or depots without losing control
  
  
• Flexibility: Participate in grid services without manual intervention
  
  
• Savings: Reduce operational costs through smart energy management
  
  

Future-proofing: Align with the latest OCPP 2.X and OCPI 2.3.0 capabilities

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How Bia Helps Fleets Move Forward

Whether you need a full CSMS with built-in smart charging or want to add smart charging on top of your existing CSMS, Bia ensures your fleet charging strategy works today — and scales tomorrow.

• Explore our Fleet Charging Solutions
  
  
• Learn more about our Technology
  
  
• Get in touch via Contact

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