Smart home tech that works off-grid

The power draw thing is exactly what caught me out. Had a Pi running HA in a shed setup, thought it'd be brilliant for monitoring the Victron—turns out I was burning through battery just to see pretty graphs.

What actually works for me now is keeping it stupid simple. Victron's own VRM portal does most of what you need without the overhead, and honestly? Check your system once a day via the app rather than having something polling sensors every 30 seconds. Game changer for battery life.

The boat's different though—I've got a proper 48V LiFePO4 setup that can handle some continuous draw, so I run a stripped-down Node-RED instance just for EV charging logic (prevents idiotic decisions when I'm trying to charge the van). But that's a deliberate exception because the math actually works.

@ZFS_OffGrid's right about the caravan rabbit hole. Depends entirely on whether your system can support it. Most off-grid setups? Genuinely can't. You're better off spending that complexity budget on getting your solar and storage right in the first place.

Good thread. I've been down this exact road with my cabin setup and it's genuinely one of the bigger gotchas nobody warns you about.

The thing is, Home Assistant itself isn't the villain—it's brilliant software. But when you're genuinely limited to, say, 10kWh a day, every watt matters. A Pi4 + PoE hat + networking gear easily becomes 20-30W running 24/7. That's 480-720Wh daily just sat there monitoring things.

What actually worked for me was being ruthless about what deserves automation off-grid. I ditched the "nice to have" stuff—weather dashboards, scene lighting, all that—and kept only what directly saved power or prevented problems. Battery monitoring through Victron's own interface, fridge/freezer alerts, that's it.

Node-RED can be lighter if you're determined to have automation, but honestly? I ended up with local MQTT sensors, a single ESP8266 handling the logic, and manual oversight for everything else. Less sexy, way more sensible on a limited system.

The mental shift is: off-

That 15W constant draw is the kicker nobody mentions, @ZFS_OffGrid. People see "low power Pi" and think it's negligible—until you're 6 months in and realise you've burned through an extra 2kWh per month just monitoring your battery voltage.

I learned this the hard way with my van conversion. Had a little Zigbee hub and some smart switches running, thought it was clever stuff. Worked brilliantly in summer when solar was generous, but come November I was rationing other things just to keep the "smart" infrastructure alive. Felt backwards.

What actually stuck with me: a simple Victron MPPT with its native remote monitoring (Victron's own app, nothing fancy) plus one decent standalone sensor for water tank level. That's it. Dropped the Pi entirely. The MPPT pulls almost nothing extra, and I get the data I actually need without the parasitic load.

The irony is the off-grid setup forces you to think clearly about what monitoring you genuinely use versus what you installed to feel smart. Wish I'd done that calculation before buying the bits rather

The real issue is phantom loads compound faster than you'd expect. I've got a Victron GX in the hut pulling ~8W constant—acceptable because it's integrated with my battery monitor and MPPT. But layering HA on top? That's when your 5kWh bank starts feeling claustrophobic. Stick with native Victron dashboards or a properly gated Shelly setup instead. The extra 15W costs you roughly 4-5% of daily generation in winter.

On the narrowboat I learned this the hard way—went all-in with WiFi monitoring before doing the maths. The GX sits in a cupboard now, just checks battery state weekly. Killed the Shelly switches entirely, far too chatty. Turns out a basic shunt monitor and occasional manual checks costs me nothing vs the constant vampire drain. Digital overkill ain't the answer.

Are any of you actually switching stuff off at the breaker when not needed? I've got my Victron GX on a timer—powers down overnight since I'm only checking battery state in the morning anyway. Seems daft having it drain 8W continuously when you could just manually check once a day. What am I missing about needing it live 24/7?