Anyone else using a Raspberry Pi to log their battery data overnight?

Been running a Pi Zero W with a Victron SmartShunt for about eight months now and the overnight graphs are either deeply satisfying or absolutely soul-destroying depending on whether I remembered to close the motorhome skylight before a cloudy Welsh night 🌧️

The setup feeds into InfluxDB and I've got Grafana running on it — took me three weekends and most of my remaining dignity to configure, but now I can see exactly when my 200Ah Fogstar Drift LiFePO4 starts getting grumpy about voltage sag.

What I'm actually logging:

• State of charge every 5 minutes
• Cell temps (paired with a Dallas DS18B20 sensor bodged on with thermal paste and optimism)
• Any Victron MPPT charge controller activity

The real revelation was discovering my fridge compressor kicks in at 3am and hammers the battery harder than I'd thought — knocked nearly 8% off overnight that I'd been blaming on parasitic draw from the Cerbo GX.

Anyone else gone down this particular rabbit hole? Genuinely curious whether people are pushing data to a cloud dashboard or keeping it local — my wife already thinks I've lost the plot, so I'm keeping everything on the Pi rather than explaining why our electricity usage is on the internet.

Also if anyone's managed to get reliable Bluetooth polling from a Victron BMV without it dropping connection every four days, I will owe you a biscuit.

@RetiredNurse49 Ha, that cliffhanger ending is very relatable — I'm guessing "charge the batteries" finishes that sentence?

I've been meaning to do something similar on my shepherd's hut setup. Currently just squinting at the Victron app on my phone at 6am like some kind of solar-anxious goblin. A Pi Zero W logging directly to the SmartShunt via the VE.Direct cable sounds much more satisfying.

Couple of questions if you don't mind:

• Are you using VictronConnect's built-in logging or pulling data via a custom script?
• Does the Pi Zero handle overnight logging without hammering the SD card? I've heard write cycles can be an issue
• What are you using to visualise — Grafana, something simpler?

My hut's only got a modest 200Ah Fogstar setup so the graphs might be more "gentle slope" than drama, but I'd still love to track it properly.

@RetiredNurse49 Been meaning to do exactly this on the narrowboat — currently just checking the Victron app manually each morning which feels very Stone Age. Couple of questions if you don't mind:

• Are you pulling the data via the SmartShunt's Bluetooth or have you wired something directly?
• How much storage does eight months of overnight logs actually eat up on the Pi?

The boat setup complicates things slightly because I'm often in tunnels or cuttings with zero signal, so I'd want everything logging locally rather than relying on any cloud connection. Guessing the Pi Zero W handles that fine? Also wondering whether it's worth jumping straight to a Pi 4 for headroom or if the Zero W genuinely does the job without struggling.

@RetiredNurse49 I've got almost the same setup in my shepherd's hut — Pi Zero W talking to a Victron SmartShunt via Bluetooth, dumping data into a little InfluxDB/Grafana stack. The overnight graphs are genuinely addictive once you get them going.

Couple of questions though — are you pulling data through the VictronConnect API or did you go down the vedirect serial cable route? I went serial because Bluetooth polling felt flaky at 3am when nothing else is awake to annoy it.

Also, what voltage are you calling "soul-destroying"? I've started colour-coding mine so anything below 12.1V goes red. Mostly so I can have a quiet existential crisis in a visually organised fashion.

@VivaroProject the narrowboat use case would be interesting — do you have much voltage sag with a bow thruster or is it mostly domestic loads?

@RetiredNurse49 Running almost identical on the boat — Pi 4 though, because I wanted the headroom for a bit of extra processing. The overnight graphs genuinely changed how I manage the system. I spotted a phantom load I'd completely missed for months — a 0.3A drain that was silently murdering my Fogstar 200Ah over winter. Never would have caught it just eyeballing the Victron app.

@VivaroProject the manual checking trap is real. You think you're on top of it until one cold morning proves you weren't.

One thing worth adding for anyone setting this up — store your data locally first, don't rely on cloud connectivity. On the water, my WiFi signal does what it likes at 2am.