Anyone else finding EV charging off-grid genuinely painful in winter?

Running a Victron Multiplus II (5kVA) with 15kWh of Fogstar Drift LiFePO4 and a 4kW array on the cabin roof. Summer's brilliant — I can top up the van to about 80% before noon and still have plenty left for the cabin loads. Winter is a completely different story. Yesterday I had maybe 600W of solar by midday and the battery was already down to 40% from overnight heating.

I've been throttling the EVSE right down to 6A (1.4kW) to try and keep things manageable, but even that feels like it's robbing Peter to pay Paul. The Cerbo GX lets me automate charging windows which helps a bit, but you're still fighting against a 30–40% drop in usable capacity when temps hit single figures.

Curious whether anyone's gone down the route of a small dedicated generator purely for EV top-ups in winter, or whether that defeats the whole point. I've also been eyeing up the Renogy 400W flexible panels for extra roof space but the cabin pitch is awkward and shading from the trees kicks in around 2pm. What's everyone's winter EV charging strategy — or have most of you just given up until April?

@FormerCop77 oh mate, I feel this post in my soul.

My setup's a bit more modest — 10kWh Fogstar and a 3kW array on the static — and winter EV charging has become this whole strategic operation rather than just... plugging in.

What actually saved my sanity was shifting to overnight charging from the grid when rates drop (on Octopus Go), then using the solar to top back up the battery bank during the day. The Victron essentially becomes a buffer rather than the primary source.

The real villain nobody talks about is charging efficiency in the cold — your EV's battery management system is working against you at the same time your panels are underperforming. It's a double squeeze.

Have you tried throttling the charge rate right down to 6A? Less efficient overall but stops the Multiplus from working itself into a panic.

@FormerCop77 this is exactly why I stopped trying to charge the boat's service bank and run the inverter simultaneously in December. The maths just doesn't work when you're getting three hours of usable solar and the panels are half-shaded by a bridge or a tree line.

What shifted things for me was accepting that winter means prioritising. The van gets a top-up only after the domestic bank hits 80%+, full stop. Painful when you need a run to town, but it stopped me doing that horrible thing where you drain everything chasing a percentage.

Also — have you tried throttling the charge rate right back on grey days rather than letting the Multiplus hammer away at whatever the array can scrape together? Smaller consistent draws seem to stress the system less when generation's patchy.

Spent last December genuinely rationing my van charging like it was the 1970s energy crisis.

The thing nobody tells you before you build one of these systems is that winter isn't just about reduced solar hours — it's the combination of reduced hours, lower panel efficiency in the cold, and the van's battery management system demanding more current to warm the pack before it'll even accept a fast charge.

My Victron MPPT logs from January told a brutal story. Some days I was seeing maybe 40% of rated output before 11am, and by 3pm it was already dropping off a cliff.

What actually saved me was setting a strict priority schedule on the Multiplus — van charging only happens in that 11-to-2 window now, regardless of state of charge. Less convenient, but the battery bank stopped looking ragged by February.

Hey @FormerCop77, similar setup here and yeah, winter is properly humbling.

One thing that's helped me is shifting to overnight DC-DC charging from the van's alternator on driving days rather than relying solely on solar. Not glamorous but it offloads some pressure from the house batteries when generation is miserable.

Also worth having a proper look at your charge scheduling in VRM if you haven't already — I set mine to prioritise van charging in a tight window around solar noon rather than letting it trickle all day. Concentrating the load when the panels are actually doing something makes a surprising difference.

Still doesn't fully solve it, but I've stopped feeling quite so defeated by a cloudy January. The 5kVA Multiplus should handle the current draw fine at least — that bit's not your problem! 😅