Anyone else using a Raspberry Pi to monitor their off-grid setup? Sharing what I've cobbled together

I've been running a small off-grid solar setup at our place in rural Wales for about two years now — 400W of panels, a Victron SmartSolar 100/30 MPPT, and a 200Ah lithium battery. For ages I just relied on the Victron Connect app on my phone, which is fine but felt a bit passive. A few months back I decided to have a go at pulling data into a Raspberry Pi 4 and logging everything properly, and honestly it's been a bit of a rabbit hole.

At the moment I've got the Pi reading from the MPPT via a VE.Direct to USB cable, logging to InfluxDB, and displaying on a Grafana dashboard. I can see daily yield, state of charge over time, absorption vs float hours — all that good stuff. It's massively helped me understand what the system is actually doing, especially spotting that one of my panels was underperforming due to partial shading I hadn't noticed. Saved me a fair bit of head-scratching.

What I'm struggling with now is adding my inverter (a Victron Phoenix 12/1200) and a clamp meter on the AC output side so I can see actual load consumption in real time. I've had a look at ESPHome and Node-RED as options for pulling in extra sensors but I'm not sure which direction is most sensible. Has anyone integrated a CT clamp — something like the YHDC SCT-013 — into a setup like this, and if so what did you use to read it? A dedicated energy monitor board like the emonTx, or just straight into an ESP32?

@LindaCross66 — welcome to the forum, good to have someone from rural Wales on here!

Pi monitoring is absolutely the way to go once you're past the "just checking the Victron app" stage. I've got a Pi 4 on my narrowboat pulling data from a Cerbo GX via MQTT, feeding into InfluxDB and Grafana. The historical charts are genuinely useful — spotted a failing cell in my Fogstar battery way before the BMS would've flagged anything obvious.

Few things worth looking at:

• VictronConnect local API — surprisingly well documented
• Node-RED — easier than raw Python for wiring things together if you're not a coder
• pvoutput.org — worth logging to for long-term yield comparisons

What are you using to pull data off the SmartSolar — Bluetooth polling or have you wired anything in directly?

Really nice setup @LindaCross66! I've got something similar running here in Cumbria. One thing I'd add to whatever you've cobbled together — make sure you're logging to a local database (I use InfluxDB) rather than relying solely on cloud services. Learned that the hard way when my internet went down for three days during a storm and I lost all that monitoring data.

Also worth looking at Grafana for visualisation if you haven't already — the dashboards are brilliant once you get them configured, and you can set up alerts to ping your phone if the battery drops below a certain state of charge overnight.

Are you pulling data directly from the Victron via VE.Direct to the Pi? If so, the vedirect Python library makes life much easier. Happy to share my scripts if useful.

Great thread! @LindaCross66 I'd strongly recommend looking into Grafana + InfluxDB for visualising your data once you've got the Pi pulling stats from your Victron kit. The VRM portal is decent but having your own local dashboard with historical graphs is on another level entirely.

I run a Node-RED flow on mine that sends me a WhatsApp alert if the battery drops below 20% SOC overnight — saved me a few times when I'd left something drawing more than expected. Took an afternoon to set up and cost nothing extra.

One practical tip: stick the Pi somewhere it won't get too cold if you're in Wales — mine throttled badly last winter sitting near an uninsulated wall. A small enclosure sorted it.

Happy to share my Node-RED flow if anyone wants a starting point. It's rough round the edges but it works! 🙂

Been running a Pi on the narrowboat for about eighteen months now, pulling data from the Victron via VE.Direct cable — proper game changer compared to squinting at the SmartSolar display.

The bit nobody mentions until it's too late: power the Pi from a decent DC-DC converter, not some cheap USB adapter. Lost two SD cards before I worked out the culprit was dirty voltage from the boat's 12V rail causing corrupt writes.

Also worth logging ambient temperature alongside your battery data — I noticed my Fogstar cells start behaving oddly below about 8°C, and having that correlation in the logs made it obvious what was happening rather than just blaming the solar.

@DuctTapeDave94 the Grafana route is brilliant once you're ready for it, but @LindaCross66 honestly start simple — just CSV logging to a USB stick first. Get comfortable before adding complexity.

Running a very similar setup on both my garden office and the boat — Pi Zero 2 W works a treat for this kind of monitoring without drawing much power itself (important when you're being careful about every watt).

One thing nobody's mentioned yet: if you're pulling VE.Direct data, have a look at the vedirect Python library rather than rolling your own serial parsing. Saved me a lot of headache.

Also worth setting your Pi to read-only filesystem mode — I lost two SD cards to corruption before I got round to it. OverlayFS is your friend. Logs to RAM, critical data writes to a proper USB stick or SSD instead.

@LindaCross66 what are you planning to do with historical data once you've got it collecting? That's where it gets properly useful for spotting patterns in your generation and consumption.