Wattcycle 12kw inverter - Homeassistant Solarman integration

Been eyeing up the Wattcycle units for a while now as a possible upgrade for my static caravan setup. The Solarman integration with Home Assistant is honestly one of the biggest selling points for me over some of the other options at that price point.

Has anyone actually got this running stably? I've seen a few threads on other forums where people are getting dropouts every few hours and having to restart the integration. Not ideal if you're trying to do any meaningful automation.

My current setup is Victron kit throughout so I'm spoiled with how solid the VRM and HA integration is there. Would be moving away from that ecosystem which gives me pause.

A few things I'm specifically curious about:

• Polling interval — what are people running without hammering the device?
• MQTT vs the native Solarman integration — is one noticeably more reliable?
• Modbus — does the 12kw unit expose enough registers to make direct Modbus worth the effort instead?

Also wondering if anyone's running this in a garden office or similar smaller install rather than a full house setup. My use case is more emergency backup than primary off-grid, so I don't need every sensor working perfectly, just the core SOC and power flow data reliably.

Genuinely interested in hearing from anyone who's had it running for more than a few weeks rather than initial impressions. The first few days always seem rosy with these integrations before the edge cases start appearing.

@RetiredPlumber Before you commit, can I ask how reliable the Solarman API actually is in practice? I've seen mentions elsewhere that the cloud dependency is a significant weak point — if Solarman's servers go down or they change their API, your HA integration presumably breaks entirely.

Is there any local LAN-based communication option with the Wattcycle units, similar to how Victron handles things via Modbus or the GX ecosystem? That would be far more robust for automation purposes.

Also curious whether the integration exposes proper energy entities that play nicely with HA's Energy Dashboard, or whether you're having to bodge it with template sensors. I'm mid-way through a van conversion at the moment but planning a static setup next, so trying to understand which inverter ecosystems actually deliver on the monitoring promises before I spend serious money.

@FormerMariner1 good question actually — I'd also want to know whether it's the local API or the cloud-based one people are relying on. From what I've read on here and a few Reddit threads, the cloud API can be flaky and occasionally drops out for hours at a time, which would drive me absolutely mad if I'm trying to monitor my cabin setup properly.

Has anyone got the local polling working with it? That's the bit I'd need confirmed before parting with money on a 12kw unit.

Also @RetiredPlumber — static caravan use specifically, are you planning 3-phase or single phase? And what are you replacing? Curious whether the Wattcycle actually improves on something like a Victron Multiplus in real-world terms or whether it's just cheaper on paper.

@LisaStewart71 @FormerMariner1 — worth clarifying this distinction properly because it matters enormously for reliability.

The local API (via the Solarman integration's station/logger approach using port 8899) bypasses Solarman's cloud entirely. Polling interval can be as low as 10–30 seconds and it works completely offline. That's what you want.

The cloud-based route depends on their servers staying up, which historically they don't — there have been notable outages, particularly affecting European users during peak hours.

For my garden office setup I run the local integration via a static IP reservation on my router pointing to the data logger dongle. Been rock-solid for eight months. The HA integration is solarman-mqtt or the native HACS solarman integration depending on your firmware version.

@RetiredPlumber — check which data logger comes bundled with the Wattcycle unit before purchasing. The LSW-3 vs LSE dongles behave differently.

@LochSpirit raises a really important point — I've been through this exact rabbit hole with my Cerbo GX and various integrations.

Genuinely curious whether the Wattcycle/Solarman local API requires any port forwarding or specific firmware versions to enable? With my Victron setup I had to dig around quite a bit before local comms worked properly without touching the cloud at all.

Also — does anyone know if the Solarman integration in HA supports two-way control, or is it purely read-only? For a cabin or boat setup that's a dealbreaker for me. Being able to push charge limits or switch modes from HA automations is what I actually need, not just pretty dashboards.

Has anyone tested latency on the local vs cloud polling? I've seen the cloud route introduce 30-60 second delays which makes automation logic pretty useless in practice.

Great thread timing for me — I've just finished setting mine up last week! To add to what @LochSpirit and @Cerbo_Queen are touching on, with the Wattcycle I'm using the local API via the Solarman integration in HASS and it's been rock solid. No cloud dependency, polls every 30 seconds without issue. The key thing @RetiredPlumber will want to know is that you need the WiFi logger's serial number and local IP address to configure it — make sure you set a static IP in your router for the logger stick otherwise it'll drop off periodically. Took me an afternoon to get everything dialled in but the entities that come through are really comprehensive — battery SOC, PV watts, grid import/export, the lot. For a static caravan setup it's honestly brilliant for automations around load shifting.