Can you charge an EV from a static caravan's off-grid solar setup without killing your batteries?

I've got a fairly decent setup on my static — 4× 200W panels, a Victron SmartSolar MPPT 100/30, and a 200Ah Fogstar Drift LiFePO4 battery. Works brilliantly for day-to-day loads (fridge, lights, a bit of 240V via a Victron MultiPlus 500VA). But I'm now wondering whether I could realistically trickle-charge my EV from it on sunny days.

The car is a Nissan Leaf (24kWh battery, usually sitting at around 40–60% when parked up). Even at a Mode 2 granny charge via a 3-pin socket that's pulling roughly 1.8–2.4kW — which is way more than my inverter can handle, let alone what the panels are actually producing on a decent UK day (maybe 500–700W peak realistically).

Has anyone actually managed EV charging from an off-grid solar setup without it wrecking their battery bank? Would I need a much bigger inverter, more panels, or is this just a fundamentally bad idea unless you go full-on 10kWh+ storage? Interested in what others have actually tried rather than the theoretical maths.

@IvyWalker curious about this too — I've been wondering the same for my boat setup which is similar spec to yours.

The maths worries me though. Most EVs want at least 7kW for a meaningful charge, and your 200Ah battery is what, ~2.5kWh usable? You'd drain it completely for barely 10-15 miles of range, and that's before accounting for inverter losses.

Is your use case genuine daily charging or purely emergency top-up? Because those are very different problems. For emergency backup purposes I could see doing a slow trickle via a proper inverter-charger, but I'd want to know:

• What inverter are you running?
• Are you grid-tied at all or fully isolated?

The Victron 100/30 is also only pulling ~400W max from those panels — feels like the bottleneck is well before the battery.

@IvyWalker short answer: yes, but carefully. Your 200Ah Fogstar gives you roughly 2.5kWh usable — that's maybe 8-10 miles of EV range if you drain it completely, which you obviously don't want to do.

The real constraint isn't the battery, it's your MPPT. The 100/30 caps you at around 400W input on a good day, so charging even at 1.4kW (a standard granny charger) is going to pull from the battery faster than solar replenishes it.

What actually works:

• Midday solar surplus charging only — set a high SOC trigger (90%+) before you plug in
• Keep sessions short, 20-30 mins max
• Watch your Victron app like a hawk

I've done it on a similar setup with my Leaf. It's more of a "top-up while the sun's cracking" situation than a proper charge strategy.

@IvyWalker one thing worth adding to what @T5Wanderer said — keep an eye on your charge rate going into the EV, not just what's coming out of the battery. Most EVs will try to draw 3.6kW minimum on a Type 2 connection, which would absolutely hammer your setup. You'd want a granny charger (3-pin) with a rate limiter, or look into something like a Hypervolt that lets you dial the amps right down — some can go as low as 6A (1.4kW). That way you're topping up gradually rather than demanding everything at once. Solar-direct charging on a sunny day is the sweet spot really, keeping the battery as a buffer rather than the primary source.

@IvyWalker worth checking your EV's minimum charge current too — some won't accept below 6A on a Type 2, which is 1.4kW. Your whole solar array on a good day might only push 600-700W into the battery after losses. So you could end up in a situation where the car simply refuses to charge at all unless you've got a decent state of charge built up first.

On my narrowboat I run a similar Fogstar 200Ah bank and I'd never try direct EV charging without a significant buffer. The maths just doesn't stack up unless you're letting the battery accumulate energy over several hours before you plug in — treat it like filling a bucket, then tipping it rather than trying to run a hose straight through.

A Zappi charger with its "eco" modes can help manage this intelligently if you want to go further down that route.

Really good point from @Spud79 there. One thing nobody's mentioned yet — your inverter is going to be the hidden bottleneck. To pull even 6A at 230V you're looking at roughly 1.4kW continuous, which means your inverter needs to handle that comfortably and your 200Ah battery needs to sustain it without tripping any low-current protections. Check what continuous discharge your Fogstar BMS is rated for — most Drift batteries are fine, but sustained high draws over several hours are a different matter to occasional peaks. Also worth charging during peak solar hours so the panels are contributing directly rather than just draining stored capacity. A cloudy afternoon session will chew through your bank surprisingly fast.

Great points all round. Just to add something nobody's touched on yet — your State of Charge window matters enormously here. I'd strongly recommend not letting that Fogstar Drift drop below 20% SoC whilst EV charging is pulling current. LiFePO4 is forgiving, but sustained high discharge combined with cloud cover rolling in unexpectedly can leave you with nothing for evening loads.

Consider setting a low SoC cutoff in your Victron to halt EV charging automatically — the SmartSolar can communicate with some EVSE controllers depending on your setup. Even a simple timer to restrict charging to peak solar hours (say 10am–3pm) would give you a decent buffer.

You'll never get massive range from a session like this, but topping up 10–15 miles on a sunny afternoon is genuinely achievable without hammering your system. 🙂