Anyone else struggling to keep leisure batteries topped up in winter with just solar?

Winter solar is genuinely brutal, isn't it? I made the switch to lithium a couple of years back — Pylontech US2000s paired with a Victron MPPT — and even I struggle to pull meaningful charge through December and January up here.

The fundamental problem is you're fighting on two fronts simultaneously: the panels are producing a fraction of their rated output, and you're drawing more from the battery because heating, lighting, everything runs longer. It's a perfect storm.

A few things that made a real difference for my static setup (though the principles carry across to motorhomes):

• Panel tilt angle — winter sun sits low, so steepening the angle can recover surprising amounts of generation
• Keeping panels clear — frost and leaf debris absolutely kills output, worth checking more often than you'd think
• A secondary charging source — even a modest 240V hook-up occasionally, or a DC-DC charger running off the engine, takes the pressure off entirely

The honest answer for longer off-grid winter stays is that solar alone probably isn't going to cut it without a decent backup strategy. I see a lot of people on here chasing bigger panel arrays when actually shore power access or a small generator used occasionally would solve the problem more cost-effectively.

What's your current setup — lead-acid or lithium? That changes the conversation quite a bit because lead really doesn't like sitting partially discharged through cold snaps. Curious whether others are finding the same pattern or if anyone's cracked a genuinely solar-only winter solution?

@Pylontech_Queen not a motorhome setup here but I run a static caravan off-grid with a Fogstar Drift 200Ah and a pair of Renogy panels on the roof — December and January are genuinely grim. Some days I'm getting maybe 40W through a 400W array. Embarrassing numbers.

What saved me was adding a small Honda generator on a timer for a 2-hour absorption top-up on the dark days. Not glamorous, not pure off-grid, but it keeps the BMS happy and stops me stressing about the batteries sitting at 60% for weeks on end.

Solar alone in a British winter is a fantasy unless you've got panels practically carpeting your roof. The low sun angle absolutely kills efficiency — panels that work brilliantly in June are basically decorative in January.

@Pylontech_Queen this is exactly why I built my emergency backup around a DC-DC charger rather than relying on solar alone through winter. Even with decent south-facing panel orientation, you're sometimes pulling 30-40W on a grey December day when you need 300W+ to properly cycle lithium chemistry.

What's your split charging arrangement when driving? A quality Victron Orion-Tr Smart between alternator and battery bank can genuinely save you in the darker months — I keep mine set to absorption at 14.2V for my LiFePO4 cells and it makes a substantial difference over a 2-3 hour motorway run.

Solar shouldn't be your only input strategy between October and February in the UK. Treat it as supplementary and design your system around that assumption from the outset.

@Pylontech_Queen feel this hard. Running a 200Ah Fogstar Drift in the van with a Victron SmartSolar 100/30 and honestly December/January are a write-off for solar alone.

What's saved me is a B2B charger wired to the alternator — Sterling Pro Batt Ultra 60A. Even a 45-minute motorway blast puts back more than a full winter day on the panels. Combined with keeping my usage lean (12V compressor fridge is the main load), I can manage indefinitely without hookup.

The other thing people sleep on is panel angle. Flat roof-mounted panels are terrible in winter sun — the elevation is so low you're barely catching anything useful. Even propping them at 45° when parked makes a noticeable difference on my MPPT app.

Lithium definitely helps with usable capacity but it's not a magic fix for generation problems.

Really relate to this. Got a garden office setup rather than a van but the winter solar struggle is real regardless of application. On my worst days in December I was seeing maybe 20–30 minutes of anything resembling useful generation.

Genuine question for the thread — has anyone experimented with tilting panels more steeply in winter to chase that low sun angle? I've been meaning to try adjusting mine from a fixed 20° to something closer to 60° and wondering if it's actually worth the faff, or whether the diffuse light conditions here in the UK make the angle largely irrelevant anyway?

@CamperWayne curious what your Victron SmartSolar data shows for worst-case December days — does yours at least recover overnight with the Fogstar's resting voltage, or are you genuinely seeing it creep down week on week?