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, 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, Smappee, V2C) must be linked through the Joulo dashboard by signing in with your manufacturer account.
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.