Charging a Leaf off a van solar setup — anyone actually done this long-term?

So I've been running a 400W roof array with a Victron SmartSolar MPPT into a 200Ah Fogstar lithium bank in my Transit conversion for about 18 months. Works brilliantly for the usual stuff — 12V compressor fridge, lighting, laptop, the odd bit of cooking off a small inverter. But I've recently picked up a used Nissan Leaf as a daily and the idea of being able to top it up on-site is doing my head in with possibilities.

The maths obviously get brutal fast. Even a slow 3kW charge for a couple of hours is asking a lot of a 200Ah bank, and realistically my array is going to struggle to keep up unless I'm parked in full sun all day. I've been eyeing up expanding to maybe 800W and bumping the battery to 400Ah, but I'm not sure if that's even enough to make a dent in a Leaf's 40kWh pack in any reasonable time.

Has anyone actually wired something like this up properly? Thinking a dedicated inverter-charger feeding the Leaf's Type 2 at minimum charge rate (about 1.4kW / 6A). Is there a point where it becomes genuinely useful versus just a faff that barely moves the needle on the Leaf's SOC? Or am I better off just accepting the van and car are separate energy worlds?

SteveGreen74 | 847 posts | ⭐ Regular Contributor

@JubileeClipHero5 Yes, done exactly this for about eight months now. The honest answer is — it works, but you're constantly robbing Peter to pay Paul on cloudy UK days.

I use a Type 2 portable EVSE wound right down to 6A (roughly 1.4kW) and only top the Leaf up when the SmartSolar is genuinely producing well. Anything below 60% SOC on my lithium bank and the charger gets unplugged immediately.

Summer was brilliant — regularly added 15-20 miles overnight from decent afternoon generation. November through February though? Forget it as a reliable strategy. You're basically just maintaining the Leaf's existing charge rather than meaningfully adding to it.

The Victron integration helps enormously — I've got a relay trigger set to disconnect the EVSE automatically if bank voltage drops below 13.1V. Saves me from making costly mistakes.

The numbers are the killer here — a Leaf pack is what, 24-40kWh depending on gen? Your 400W array on a good UK day might net you 1.5-2kWh realistically. You're looking at days of dedicated charging just to meaningfully top it up, and that's assuming you're not drawing anything else from the bank simultaneously.

The weak link is your 200Ah Fogstar acting as the go-between. Depending on which inverter you're running, you could be throttling the charge rate anyway before it even hits the Leaf's onboard charger.

Done similar experiments with a smaller EV scooter pack — even that was frustrating on cloudy weeks. Scotland in November nearly broke me 😅

Worth looking at DC-DC direct coupling if you haven't already — cuts out some of the conversion losses at least.

DazHenderson77 | 234 posts | 🔧 Member

Done similar on my static caravan setup and the maths always wins the argument — UK solar in November is basically decorative at that point, you're essentially using the Leaf as a very expensive paperweight until March. 🍂

Glen1961 | 1,203 posts | ⭐ Senior Member

@JubileeClipHero5 Worth thinking carefully about your inverter situation here. To charge a Leaf via the onboard charger you're looking at pushing 3.3kW minimum through a Type 1 connection — your 200Ah bank simply can't sustain that discharge rate without hammering it, and you'd drain the lot in under an hour anyway.

What some folk have done successfully is charge the Leaf very slowly overnight using a trickle arrangement, accepting it'll take days rather than hours. Not ideal if you're actually driving the Leaf anywhere meaningful.

Honestly the more practical approach I've seen work long-term is using the van solar purely for van living loads, and sourcing Leaf top-ups opportunistically from public chargers or hook-up when available. Keeps your lithium bank healthy too.

What's your actual daily mileage requirement on the Leaf?

@JubileeClipHero5 Rough napkin maths: your 400W array in the UK averages maybe 2-3 peak sun hours daily, so ~1kWh on a decent day — that's approximately 1/24th of a 24kWh Leaf pack, meaning you'd top up roughly 4% charge overnight if you're lucky and the clouds behave, which they won't because this is Britain.

Right, so I've actually been down this rabbit hole — not with the Transit specifically, but charging my narrowboat's PHEV from a 600W array on the cabin roof.

The bit nobody mentions is the charging profile mismatch. Your Victron MPPT is happily sitting at 14.4V doing its thing, then you lob a DC-AC inverter in, run it to a 7kW EVSE, and wonder why your efficiency numbers look like they've been through a blender.

What actually worked for me was going slow and intentional — a basic 3kW mode on a Type 2 lead, accepting it'll take days not hours, and only doing it when the battery's genuinely full and sun's cracking.

Treat it as topping-up between proper charges rather than a primary source and the maths stops being so savage.

The Leaf's onboard charger will happily throttle down to whatever your inverter can sustain, but your 200Ah Fogstar is basically donating a kidney every time you plug in — you'll be cycling that bank hard enough to make Fogstar's warranty department nervous.

DodgyHermit | 847 posts | 🌿 Regular

Running something similar on my shepherd's hut setup rather than a van, but the fundamentals are identical. The Leaf's onboard charger will pull 3.3kW minimum — your 200Ah bank simply cannot sustain that draw without collapsing voltage and tripping protection.

What @BatteryAlan is gesturing at is the ratio problem, not just daily yield. Even if you accumulate enough solar kWh, your battery can't deliver it fast enough.

You'd realistically need to either:

• Expand to a proper 400Ah+ bank
• Add a DC-DC boost arrangement
• Accept trickle-opportunistic charging (genuinely slow)

The Leaf also gets grumpy below certain charge rates — worth checking Speakev forums for specifics.