EV charging from solar — is it practical?

Been looking at this seriously for a while now. I've got about 8kW of solar across my barn roof, split between two strings feeding into a Victron MultiPlus, and I'm thinking about adding a home charger for an upcoming EV purchase.

The maths seem mental though. A full charge is what, 50-70kWh depending on the car? Even on a cracking summer day I'm only generating maybe 6-8kW peak, and that's assuming no clouds and it's actually noon. Winter is basically a non-starter.

My actual question: are people here doing this as a genuine primary charging method, or is it more supplementary? I'd still need grid connection anyway for reliability, so I'm wondering if the whole exercise is just added complexity and cost for marginal benefit.

I've read about some setups using smart chargers that grab excess solar in the afternoon, but I don't have a battery bank big enough to store meaningful amounts — my Fogstar system is only 10kWh and that's already allocated to evening loads.

Should I just accept I need a standard EV charger that pulls from grid when solar isn't cutting it? Or am I missing something about how people are actually making this work practically in the UK climate?

Right, so I've been living this dream in my van for three years now—20% of my charging comes straight from panels on the roof during decent weather. The maths are brutal though.

Your 8kW setup sounds decent, but here's the reality: an EV needs roughly 7-10kW to charge meaningfully. That's your entire solar output just sitting in the car, not powering your house, fridge, or anything else. Winter? Forget it.

What actually works is treating solar as supplementary. I charge opportunistically on sunny days, and grid-top-up otherwise. Get a Victron MPPT controller (you've probably got one already) feeding into a dedicated circuit rather than trying to squeeze it through your MultiPlus—less conversion loss.

If you're serious, consider a smaller dedicated string with a dedicated charger. But honestly, without batteries, you're chasing marginal gains. Battery storage changes the equation entirely though.

What's your battery setup currently?

Practical? Yeah, but depends on your setup and driving habits. I've got 6kW on the boat and charge when conditions are decent—works brilliantly May through September, nightmare in winter.

With 8kW you're in decent territory. The key thing is battery buffering—don't try to charge the EV directly from panels or you'll wreck your MPPT. Size a proper battery bank first, then pull from that when solar's generating. Victron gear plays nicely with most EV chargers if you get one with load control.

Real talk though: if you're doing daily commuting, you'll still need grid most of the year unless you've got serious battery. Works great as a supplement though. Summer road trips? Basically free.

What's your battery situation like currently?

The practical bit really comes down to whether you're willing to be flexible with when you charge. I've got a Renogy 8kW array feeding a Victron MPPT, and I charge my EV whenever I've got decent solar coming in—usually midday through to mid-afternoon in summer, absolutely nowhere in winter.

What works for me is setting expectations low. On a cloudy week in January, I'm pulling from grid like everyone else. But May through September? That's when I genuinely offset most of my charging. The MultiPlus you've got is a cracking foundation—you're already halfway there.

The real kicker is battery storage. Without it, you're bound to whatever the sun's doing that exact moment. I've been eyeing a Fogstar battery module to smooth things out, but that's a proper investment.

Depends if you're chasing "solar powered" as a nice bonus, or as your actual strategy.

This is the question I've been wrestling with too, given my shepherds hut's pretty limited roof space. Eight kilowatts is a decent starting point though.

What's your battery storage like? That's the crux of it for me—if you're relying on real-time solar without decent battery capacity, you'll end up grid-charging during cloudy spells anyway. The Victron kit you've got should handle the logic well enough.

Have you looked at what your actual driving pattern is? I'm asking because winter charging from panels feels optimistic round here. Summer's different—that's when the maths starts working.

Also worth considering: are you planning a dedicated EV charger or something that can play nicely with your existing MultiPlus setup? Some of the wall units don't communicate well with battery systems, which rather defeats the purpose of having 8kW of panels.

What's drawing the most power in your setup currently?

The real question isn't whether it's possible — it's whether you're prepared to work with the sun rather than against it. I've been running this dance for three years now with my shepherds hut setup, and honestly, it's transformed how I think about energy use.

Eight kilowatts is a solid foundation. The catch is that most EVs want to charge at 7-11kW, which means you're banking on clear skies and midday windows. I've found battery storage is the actual game-changer here — I buffer excess generation into a Victron battery bank, then feed the car from that when conditions dip. Seasonal variance is brutal too. Summer? Brilliant. January? Expect to grid-top-up.

@VivaroBuild nailed it about flexibility. If you can wait for decent weather windows rather than demand a full charge by Thursday, you'll love it. Otherwise you're fighting physics.

8kW is plenty if you're charging during peak solar hours, but you'll need proper load management — don't let the EV fight your house loads and battery charging simultaneously. My setup runs a Victron MPPT controller with a basic relay that kills the charger input if my battery state drops below 80%, forces me to be disciplined about timing.

The real bottleneck isn't generation, it's storage. You'll burn through that battery bank ferociously powering a 7kW charger, so unless you've got serious capacity behind that MultiPlus, you're mostly just converting solar directly to motion—which isn't bad, just means you're tethered to the weather.

Winter charging becomes fiction, obviously. Works brilliantly June through September if you're patient.

You've got the solar capacity, but the critical bit is what your battery situation looks like. Eight kilowatts of generation isn't the same as eight kilowatts available to the car—you're already feeding the MultiPlus and house loads.

If you're thinking grid-tied with battery backup, you could use excess solar to charge during peak hours and pull from batteries off-peak. If you're fully off-grid, you'll need substantial storage (15–20kWh minimum realistically) to make daily charging viable without relying on a petrol backup.

Have a look at DC coupling a Victron MPPT directly to the car's onboard charger if possible—cuts out inverter losses. Some folks on here have had success with that approach.

What's your current battery capacity and daily usage pattern? That'll determine whether this is straightforward or requires careful juggling.

The elephant in the room that @FenlandSolar's hinting at: your MultiPlus setup matters enormously here. Are you running a battery bank behind it, or grid-tied? That's the actual constraint.

If you've got decent battery storage (say, 15-20kWh usable), you can absolutely charge an EV from solar — I've done this with my narrowboat setup using a smaller Victron stack and it's genuinely viable. Charge the batteries during the day, feed the car overnight or during poor weather.

Without storage though, you're chasing the sun in real-time, and most EVs won't play ball with that variability — they need stable power delivery.

What's your current battery capacity and chemistry? That'll tell you whether you need to think about additional storage or if you're better off using a dedicated MPPT charger (like a Renogy or similar) to trickle-charge when grid isn't available.

The practical answer depends heavily on your battery capacity and whether you're charging from surplus or drawing it down. I've got a similar setup in my motorhome (smaller scale, granted) and the difference between "it works" and "it actually works well" is having enough storage to buffer between generation and demand.

If you're grid-tied or have a decent battery bank, you can absolutely charge during peak hours — solar EV charging is genuinely the sweet spot. But if you're running lean on battery, you'll find yourself grid-supplementing constantly, which rather defeats the purpose.

What's your current battery size? And are you looking at a Zappi or similar load-shifting charger, or standard 7kW unit? That'll determine whether this is straightforward or needs some creative load management.

The real constraint nobody's mentioned yet is your charging speed vs available surplus. Even with 8kW of solar, you're looking at maybe 3-4kW actually available for the car most days because your house and battery management eat the rest.

I've got a similar setup with a Victron MPPT (not MultiPlus) and learned the hard way that DC charging direct from panels works better than trying to push through the inverter. Have you considered a dedicated solar charge controller feeding a CCS home unit? Renogy and Victron both do reasonable controllers now.

The seasonality question is killer too. Summer? Fine. November? Your 8kW becomes 2kW on a decent day. That's a 30-minute top-up if you're lucky.

What's your actual battery capacity?

The practical side: you'll need to be ruthless about when you charge. I've got 6kW feeding a static caravan setup, and I learned quickly that trying to charge an EV during marginal sunlight just tanks everything else.

Your 8kW sounds decent on paper, but factor in:

• Caravan fridge, lighting, heating running simultaneously
• Battery management — you'll want to prioritise keeping reserve capacity
• The Victron's switching overhead when you're juggling multiple loads

If you've got decent battery storage already, use a dumb timer to charge only when your SOC's comfortably above 80% and you're genuinely exporting. Otherwise you're just cycling your battery harder for no gain.

What's your current battery capacity looking like? That's the real limiting factor here, not the solar generation.

The missing piece here is your battery capacity and DoD tolerance. I'm running 48V LiFePO4 (15kWh usable) with 6kW solar, and I can tell you it's absolutely workable—but only if you're disciplined about charging timing.

@DefenderLife's right about the speed constraint. A typical 7kW home charger will drain your battery faster than midwinter solar can replenish it. Summer? Different story entirely. I charge my EV mostly between May and September when I've got genuine surplus after the house loads are covered.

The Victron gear will handle the logic, but you'll want a proper solar diverter or AC coupling setup to prevent draining your battery into the car. Worth looking at Fogstar's offerings if you want something tailored to off-grid scenarios.

Real talk: if you're expecting year-round EV charging from your setup, you'll need either significantly more battery or accept that winter charging comes from grid top-ups. Eight kilowatts is decent but not enormous once you factor in house consumption.

What's your actual battery capacity and typical winter/summer loads

The timing thing is key, yeah. I've got a motorhome setup with 5kW panels and learned quickly that EV charging eats through surplus fast — you're looking at needing genuine excess after batteries are topped up and the house is sorted.

Real talk: 8kW is decent but not huge for charging. A standard home charger pulls 7kW+, so you're only getting charge when you've got near-perfect conditions and nothing else drawing power. Winter's brutal for this.

Worth considering a smart charger that can throttle down to whatever surplus you've actually got — Zappi-style setup if you want to stay independent. Means you're not sat waiting for conditions or oversizing everything.

What's your battery situation like? That's what @LiFePO4Fan's getting at — if you're running small capacity or high DoD tolerance, you might be pulling so much back into the house that there's bugger all left over for the car anyway.

The thing that's not being mentioned enough: what's your battery size and what state is it in when you want to charge?

I've got a modest setup on my boat — 4kW solar, 10kWh LiFePO4 — and I learned pretty quickly that you can't just start throwing an EV charger at the array. You'll drain your battery doing it.

The way I see it, you'd need either:

• Massive battery (like @LiFePO4Fan's 15kWh, minimum)
• Or strict rules: only charge when solar's genuinely kicking out, batteries are at 80%+, and you're okay with stopping mid-charge if clouds roll in

Have you worked out your actual winter solar output? That's where most people come unstuck. Your 8kW sounds decent but if you're in the Midlands or further north, December becomes a nightmare. You might be able to charge in summer no problem, but what about April?

What's your battery capacity currently? And are you dead set on a home charger, or would you consider timing charges around your actual solar