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.
A limit of
0 Adoes 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 thestackLevelis high enough to override existing profiles.Not a Hard Stop
Setting0 Ais not a replacement forRemoteStopTransaction.Vehicle Behavior
Some EVs may behave differently when charging is paused for longer periods.
Updated 3 months ago
