OCPP Common Smart Charging Use Cases

Overview

Smart Charging in OCPP allows you to dynamically influence charging behavior without stopping a transaction. A common use case is to pause charging temporarily and later resume charging without ending the session.

This is typically achieved by:

• Applying a TxProfile
• Using chargingProfileKind: Relative
• Setting the current limit to 0 A to pause
• Setting a value greater than 6 A to resume charging

Key Concepts

TxProfile

A TxProfile applies only to the currently active transaction on a connector.

Relative Charging Profile Kind

When using chargingProfileKind: Relative, all schedule periods are interpreted relative to the start of the transaction (t = 0).

This makes it ideal for session-based control such as pausing or resuming charging.

Use Case: Pause an Active Charging Session

To pause an ongoing charging session without stopping the transaction, apply a TxProfile with a current limit of 0 A.

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A limit of 0 A does not terminate the transaction. It temporarily prevents energy transfer.

Example: Pause Charging (0 A)

{
  "chargingProfileId": 1001,
  "stackLevel": 1,
  "chargingProfilePurpose": "TxProfile",
  "chargingProfileKind": "Relative",
  "chargingSchedule": {
    "chargingRateUnit": "A",
    "chargingSchedulePeriod": [
      {
        "startPeriod": 0,
        "limit": 0
      }
    ]
  }
}

Expected Behavior
- Charging current is reduced to 0A
- The transaction remains active
- The vehicle and charger enter a paused or suspended state
- Charging may resume automatically once a new profile is applied

Important: Some vehicles or charge points may periodically retry charging.  
To keep charging paused, ensure the profile remains active.

Use Case: Resume Charging After a Pause

To resume charging, apply a new TxProfile with a current limit greater than 6 A.

Most EVs require a minimum current (typically 6 A) to resume charging.

Example: Resume Charging (e.g. 16 A)

{
  "chargingProfileId": 1002,
  "stackLevel": 10,
  "chargingProfilePurpose": "TxProfile",
  "chargingProfileKind": "Relative",
  "chargingSchedule": {
    "chargingRateUnit": "A",
    "chargingSchedulePeriod": [
      {
        "startPeriod": 0,
        "limit": 16
      }
    ]
  }
}

Expected Behavior
- Charging resumes within a few seconds
- The transaction continues normally
- Power is delivered according to the new limit

📘

Important Notes and Recommendations

• Minimum Current
  To reliably resume charging, always use a limit greater than 6 A.

• Profile Priority (stackLevel)
  Ensure the stackLevel is high enough to override existing profiles.

• Not a Hard Stop
  Setting 0 A is not a replacement for RemoteStopTransaction.

• Vehicle Behavior
  Some EVs may behave differently when charging is paused for longer periods.