Anyone else running a static caravan on solar + lithium through the winter?

Finally got my static sorted with a proper off-grid setup after years of messing about with generators. Running 4x 200W Renogy panels on the roof (tight squeeze but managed it), feeding into a Victron SmartSolar 100/30 and a pair of Fogstar Drift 100Ah 12V batteries in parallel. Feels like a proper system now rather than the usual bodge job.

Summer was brilliant — keeping the fridge, a few lights, and the 12V TV running with no drama. Winter is where it gets dicey. Last January I was barely scraping 10-15% of rated panel output on overcast days, and the batteries were getting hammered. Had to stick a small Honda genny on it for a week just to keep things ticking.

Wondering if anyone's added more panels or gone to a higher voltage array (24V system?) to get better winter performance. I've seen folk on the narrowboat forums talk about tilting their panels seasonally — not sure if that's practical on a static roof or just more hassle than it's worth. Is there a point where more battery capacity actually helps more than more panels in winter?

VanHolly | 847 posts

@GafferTapeKing19 Nice one, sounds like you've done well getting panels on a static roof - they can be awkward shapes can't they!

I'm running something similar on my shepherd's hut, though obviously smaller scale. Winter's where it gets real isn't it - those short December days with the panels sitting at a low angle really test your setup.

Curious what you're using for heating? That's usually what kills a static's battery bank in winter. I switched to a diesel air heater (Webasto clone) rather than anything electric and it made an enormous difference to how much I'm drawing overnight. LiFePO4 handles the cold better than I expected too, though I do keep mine in an insulated box under the van steps.

What's your typical state of charge looking like on a grey January morning? That's the real benchmark! 🙂

ExPostie82 | 1,203 posts

@GafferTapeKing19 Worth checking your actual panel output with a clamp meter on a clear December day — I was shocked how far off my theoretical figures were once I accounted for the low sun angle hitting my shepherd's hut array. At 51°N in winter you're essentially losing 40-50% of rated output compared to summer peak.

The Victron MPPT will log this beautifully via VictronConnect so you can see genuine daily harvest.

One thing I'd specifically flag for a static caravan: roof loadings. Those Renogy panels plus mounting hardware add up, and static roofs aren't always rated for what people assume. Worth confirming with the park operator too — some have restrictions that'll cause grief later.

What battery capacity are you running? That'll determine whether you're genuinely comfortable over a 3-4 day overcast stretch or just scraping through.

WattAMess27 | 312 posts

@GafferTapeKing19 Great setup! One thing worth mentioning that nobody's touched on yet - watch your panel angle through December and January. Static roofs tend to be quite shallow pitch, so you'll be losing a fair chunk of potential generation when the sun's already barely scraping above the horizon. If there's any way to prop the rear of your panels up temporarily over winter (even a bit of unistrut bodgery), you can make a noticeable difference. Also curious what your overnight consumption looks like - heating is obviously the killer on a static. Are you running anything electric for warmth or relying on gas?

Robbo41 | 412 posts

@GafferTapeKing19 Good setup mate. One thing worth mentioning that catches people out with statics in winter - condensation inside the battery compartment can be a real issue when temps drop. Lithium BMS doesn't like charging below 0°C and if your batteries are under the van or in an uninsulated locker, you could be triggering low-temp cutoffs without realising and wondering why you're not taking charge on a decent day. Slap a small thermometer in there and consider some basic insulation around the compartment. Also with 800W of panels and only getting 2-3 usable hours this time of year, managing your loads in the morning window when the sun's actually doing something makes a massive difference to how you end your evenings. What's your typical daily consumption looking like?

JennyPalmer | 847 posts

Running a similar setup on our static in Wales - winter performance really depends on panel angle. Ours were flat to the roof originally and we were getting embarrassingly low yields by November. Spent a weekend fabricating some simple tilt brackets to get them up to about 35 degrees and honestly it made a noticeable difference, particularly catching that low winter sun. Not a massive faff and relatively cheap if you're handy with a grinder and some box section. Also worth saying - if you haven't already, get yourself a decent monitoring app sorted so you can actually see what you're pulling in day by day. Makes it much easier to adjust your usage habits when you can spot a run of dull days coming and decide to hold off on running the washing machine. 😄

Chippy45 | 203 posts

Nice one @GafferTapeKing19, we've got almost identical panel wattage on ours in the Peak District. One thing I'd add that nobody's mentioned yet - condensation inside the caravan can be brutal in winter and plays havoc with your battery connections and terminals over time. Worth putting a thin smear of dielectric grease on all your busbars and terminal connections before the cold sets in properly. Also if your static is unoccupied for stretches, set a low-voltage disconnect around 20% SOC rather than letting the BMS do all the heavy lifting - it'll thank you come spring. We found our consumption crept up massively just from running a small dehumidifier constantly, so factor that into your overnight draw calculations if condensation becomes an issue. What inverter/charger combo are you running?

Ken1999 | 1,156 posts

Great thread this. One thing I'd add that nobody's mentioned yet - keep a close eye on your panel angles through winter. I re-tilted mine from the standard shallow pitch to about 55 degrees come November and picked up a noticeable difference in those low sun hours. Also worth checking your battery temperature regularly if your static gets properly cold overnight - lithium BMS will throttle charging below about 5°C on most units, sometimes cut it entirely. I learned that the hard way last January! @GafferTapeKing19 what inverter/charger are you running?