Thinking about adding a small EV charging point to my off-grid cabin build — anyone done this?

Got a decent setup on the van already (400Ah Fogstar Drift LiFePO4, 600W solar, Victron Multiplus-II) and I'm now looking at replicating something similar for a small cabin I'm putting up on the same plot. The cabin will mostly be weekends and holidays but I want to be able to top up the car (Nissan Leaf, 40kWh) while I'm there without hammering the grid connection — ideally off solar during the day.

The maths feels a bit daunting. Even a 7kW home charger would obliterate any reasonably-sized battery bank in under an hour, so I'm thinking more of a trickle approach — maybe a basic EVSE set to 6A (1.4kW-ish) and just letting it run slowly through the afternoon when solar is generating well. The Victron ecosystem has the EV Charging Station NS which looks promising because it integrates with MPPT and GX devices, but the price is steep.

Has anyone actually done slow EV charging from an off-grid or hybrid setup in the UK? What battery capacity did you find you needed, and did you go full Victron or piece something together more cheaply?

@RussGreen mate, charging an EV off-grid is basically just asking your batteries to hand in their notice — unless you're running a seriously beefy system, you'll be lucky to get enough juice to roll out the driveway before the sun sets again. 🚗💀

That Multiplus-II will handle the inverter side fine, but 400Ah Fogstar and 600W solar is already doing heavy lifting for cabin loads — stacking EV charging on top is a whole new argument with physics. Realistically you'd want to look at a dedicated Type 1 tethered charger on a timer, only drawing when solar's genuinely surplus, and probably double the battery bank first.

WonkyWarden | Posts: 847

@RussGreen the Multiplus-II is a solid foundation for this — but I'd strongly suggest looking at the Victron EV Charging Station rather than a standard EVSE, purely because it integrates natively with GX devices and can throttle charge rate dynamically based on available solar and battery state. So rather than hammering your bank at 7kW, it'll trickle what's genuinely spare.

The real question is what EV you're charging and how often. Topping up a small battery (Leaf, Zoe, etc.) occasionally is very different from regularly charging a Model Y. I'd also size your cabin battery considerably larger than the van setup if EV charging is a regular use case — 400Ah will feel very tight.

What's your expected solar resource on the cabin site? That'll drive everything else really.

PylontechFan | Posts: 1,203

@RussGreen great base to build from! One thing worth considering that nobody's mentioned yet — look into a proper EVSE with adjustable charge rate rather than just a basic granny charger. Something like an Easee or Zappi (Zappi especially, as it has solar divert functionality built in) means you can set it to only draw what your system can genuinely spare. Pair that with a decent battery monitor feeding into your Victron and you can effectively queue the EV charging for when the sun's cracking it. Even dropping to 6A charging overnight from a beefy battery bank is still usable depending on your daily mileage. What car are you charging? That'll massively affect whether this is realistic day-to-day.

DaleBen | Posts: 312

@RussGreen worth thinking carefully about when you charge rather than just how. Even with a beefy battery bank, throwing EV charging at it during a run of cloudy days will absolutely floor you. I've got a similar setup at my place and ended up running a small Honda genny purely as backup for heavy loads — not ideal but it's saved me more than once.

Also, have you looked at the Zappi charger? It has an eco mode that throttles charging based on available surplus generation rather than drawing from storage. Pairs nicely with Victron kit and means you're not hammering your batteries unnecessarily. Might be worth factoring that into your cabin design from the start rather than retrofitting later like I had to. What size solar array are you planning for the cabin itself?