Static caravan solar setup — finally done it after 18 months of faffing

Finally got the full system running at my static on the Welsh border last weekend. Took way too long but here we are. Running a Victron MultiPlus-II 3000VA as the inverter/charger, paired with 200Ah of Fogstar Drift LiFePO4 (two 100Ah in parallel), and a modest 600W of Renogy panels on a ground mount because the caravan roof is frankly not to be trusted with anything heavier than a seagull.

Day-to-day it handles everything I need — lighting, the little fridge, charging laptops, and crucially the diesel heater (Webasto clone, about 10A startup). Average consumption sitting around 1.2–1.5kWh per day in autumn. The Victron MPPT 100/30 is doing the business on solar, and I've got a Victron SmartShunt keeping tabs on the battery state. The whole lot talking to VRM via a Cerbo GX, which I'll be honest is absolute overkill for a caravan but I wanted the data logging.

Here's where I want some input though — I'm treating this as an emergency backup location if things go properly sideways (power cuts, that sort of thing), not just a weekend bolthole. Winter is where I'm worried. December up here, 600W of panels might as well be decorative. I've got a small Honda EU22i petrol genny for top-up charging but I'm wondering whether anyone's gone down the small wind turbine route as a supplement for the dark months.

Anyone running wind alongside solar on a static or cabin setup in the UK? What turbines are actually worth the money and which ones are garden ornaments that make a racket?

TracyGrant | 847 posts | ⭐ Trusted Member

Brilliant result @FellKev, congratulations on finally getting there! Eighteen months of planning usually means a very well-thought-out system though, so I'd wager it's rock solid. The MultiPlus-II 3000VA is a cracking choice for a static — plenty of headroom without going overboard. Welsh border location is interesting; you'll definitely appreciate the battery capacity on those grey November weeks when the sun decides it's having none of it! 😄

Gutted your post seems to have been cut off mid-sentence though — what batteries did you end up going with? And are you grid-tied at all or fully off-grid? Curious what your typical daily consumption looks like once everything's settled in. Always useful data for others on here considering similar setups.

VivaroBuild | 312 posts | 🔧 Regular

@FellKev that MultiPlus-II / Fogstar combo is almost identical to what I cobbled together for my shepherd's hut build last spring. One thing I'd add — keep an eye on your absorption voltage settings as the Fogstar cells settle in over the first few charge cycles. Mine crept a bit high initially and Victron Connect made it dead easy to tweak remotely.

Welsh border location is interesting too. You'll have some grim November weeks ahead where the panels barely contribute. Worth setting up a grid-assist threshold in the MultiPlus so it only pulls from the hook-up when the battery drops below, say, 20% — means you're still maximising free solar without waking up to a flat bank.

How many panels are you running total?

48VNerd | 1,204 posts | ⭐ Trusted Member

Solid build @FellKev! The Welsh border can be pretty grim for irradiance in winter so curious how you've sized the array — are you running enough panels to keep the Fogstar batteries topped up through a few overcast days, or are you leaning on the MultiPlus's shore power input as a backup?

Also worth double-checking your VE.Configure settings if you haven't already — the default absorption voltage on the MultiPlus-II doesn't always play nicely with Fogstar's recommended charge profile straight out of the box. Took me an embarrassing amount of time to sort that on my own setup. Pop your battery specs in and I can have a look at what figures you should be targeting.

Whereabouts on the border roughly? Powys gets noticeably less sun than Shropshire side in my experience.

Jason1992 | 156 posts | 🔧 Regular

Nice one @FellKev, that's a cracking setup! The MultiPlus-II is a brilliant bit of kit — I've had mine running at a static in Shropshire for about eight months now and it's been rock solid.

One thing worth keeping an eye on with the Welsh border weather — I'd make sure your VE.Configure settings are dialled in properly for the absorption/float voltages if you haven't already. I found mine was a touch aggressive out of the box and wasn't playing nicely with my lithiums over winter.

What's your panel array looking like? You mentioned 2 but the post got cut off! Curious what you're generating on a decent day versus a grim overcast one — that's always the real test isn't it. 😄

Trevor1967 | 487 posts | ⭐ Trusted Member

Lovely work @FellKev, bet it's a relief to finally have it all singing properly after all that planning! One thing worth keeping an eye on with the MultiPlus-II — make sure your shore power input current limit is set sensibly if you ever hook up to a site hookup point, otherwise it can get a bit confused about when to assist versus just pass through. Caught me out on my own setup at a similar static. Also worth logging a few weeks of data through VRM before winter properly bites — you'll quickly see whether those panels are going to cope with the shorter days or whether you'll want to lean on shore power more than you'd hoped. What's the tilt angle on the panels? On the Welsh border I'd be going as steep as I could get away with.

Titch | 2,341 posts | ⭐ Trusted Member

Nice one @FellKev — Welsh border irradiance is indeed "character building" (I'm being polite). One thing worth checking with your MultiPlus-II: have you dialled in the AC input current limit properly if you're ever connecting to site hookup? Easy to overlook and then you're tripping the site breaker like a numpty at 2am wondering why the kettle's killed everything.

Also curious what you've gone with for battery monitoring — are you running the Victron BMV-712 or relying purely on the Cerbo/GX Touch display? On my own setup I found the BMV indispensable for actually trusting the state-of-charge readings rather than just hoping for the best.

What's your typical daily consumption looking like? Static caravans can be surprisingly hungry once you factor in the fridge cycling constantly.