Chargers
Understand charger objects and how Joulo represents your EV chargers
A charger in Joulo represents a physical EV charging station linked to your account. Joulo supports chargers from multiple manufacturers, all accessible through a unified API.
Charger object
{
"id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"nickname": "Garage",
"connection_type": "easee",
"status": "online",
"mid_certified": true,
"is_charging": true,
"current_session": {
"id": "f0e1d2c3-b4a5-6789-0abc-def123456789",
"started_at": "2026-04-09T08:15:00Z",
"kwh_so_far": 12.45
},
"latest_meter_wh": 5432100,
"meter_updated_at": "2026-04-09T10:30:00Z"
}Fields
| Field | Type | Description |
|---|---|---|
id | string (UUID) | Unique identifier for the charger. |
nickname | string | User-defined name, set in the Joulo app. |
connection_type | string | How the charger connects: easee, wallbox, zaptec, enphase, ocpp, smappee, v2c, or other. |
status | string | Current connection status of the charger. |
mid_certified | boolean | Whether the charger has a MID-certified energy meter for official metering. |
is_charging | boolean | Whether the charger currently has an active charging session. |
current_session | object | Active session details. Only present when is_charging is true. |
latest_meter_wh | number | Latest OCPP meter reading in watt-hours. Present when meter data is available. |
meter_updated_at | string (ISO 8601) | Timestamp of the latest meter reading. |
Connection types
Adding chargers via the API
You can register OCPP chargers programmatically using POST /chargers. The response includes the WebSocket endpoint and password to configure on your charge point:
{
"id": "b2c3d4e5-f6a7-8901-bcde-f12345678901",
"nickname": "Oprit",
"connection_type": "ocpp",
"status": "offline",
"ocpp": {
"identity": "CHARGER-001",
"endpoint": "wss://ocpp.joulo.nl/CHARGER-001",
"password": "a8f3b2e1c4d5"
}
}The OCPP password is only returned once when the charger is created. Store it securely.
Cloud-connected chargers (Easee, Wallbox, Zaptec, Enphase, Smappee, V2C) must be linked through the Joulo dashboard by signing in with your manufacturer account.
Enphase support is currently limited by Enphase API coverage and data granularity. Joulo syncs all data the API provides, but timing and session detail can differ from direct OCPP integrations.
MID certification
Chargers with mid_certified: true have a MID-certified (Measuring Instruments Directive) energy meter. This means the kWh readings are legally verifiable and can be used for official ERE-credit registration.