Victron

A Victron EV Charging Station connects through the VRM API. VRM has no session endpoint for chargers, so Joulo builds sessions from the 15-minute energy series.

At a glance

How the connection works

You create a personal access token in VRM and paste it into Joulo. The token has no expiry and needs no refresh, so a Victron connection does not go stale on its own.

Joulo resolves your VRM site and the device instance of the charging station once, then caches both on the charger.

What Joulo reads

Joulo pulls the evE energy-delta series at 15-minute resolution, stores every bucket, and materialises contiguous non-idle buckets into sessions with a 30-minute gap rule. Both steps are idempotent, so a re-run never double-counts.

Three VRM behaviours shape this, all verified against the live API:

• evE is reported per installation, never per device. Asking for a specific instance returns the same series. A site with two charging stations is therefore ingested exactly once, and the second charger is marked as a mirror.
• An empty window answers with the boolean false, not an empty list. Joulo handles that shape explicitly.
• VRM caps the 15-minute interval at about 180 days. A longer span returns success with no records. Joulo requests history in chunks that stay under the cap.

MID certification

Joulo decides from the charger catalog. The Victron EV Charging Station NS has no built-in MID meter, so it is not eligible for ERE registration as sold.

Limitations

• Session boundaries come from 15-minute buckets, so times are accurate to the quarter hour.
• History older than about 180 days cannot be fetched at 15-minute resolution.
• A site with several charging stations reports one combined energy series.

Next steps