Off-grid shed workshop — finally finished!

Right, been waiting for decent weather to get photos sorted. Finally got the shed wrapped up last month.

The Setup:

• 4x 400W Renogy panels on the roof (south-facing, obviously)
• Victron SmartSolar 150/60 MPPT — honestly the best investment, the app integration is brilliant
• 10kWh LiFePO4 battery bank (DIY'd with Fogstar cells, bit fiddly but saved a fortune)
• Multiplus 48/3000 inverter for running the workshop kit
• Basic AC coupling for future expansion

Why these choices:
Needed something robust for a proper workshop — can't have the kit shutting down mid-project. The Victron stuff is pricey but the monitoring means I actually know what's happening instead of guessing. LiFePO4 was the only sensible option; lithium prices have dropped enough that the payback's reasonable, and I wasn't keen on lugging lead-acid around.

The reality:
Winter's been interesting — panels generate bugger all in December — but summer easily covers the angle grinder and circular saw. Haven't worked out EV charging integration yet, that's phase 2.

Biggest learning: ventilation matters way more than I thought. The batteries generate heat and it all concentrates in a shed. Added a small AC unit which actually made the whole thing viable.

Cost about £8.5k all in, reckoning on 7-8 year payback if I actually use it for work projects (still working that bit out).

Happy to answer specifics on the LiFePO4 setup — did loads of research.

Decent setup! 4kW on a shed is proper serious. Guessing you're running the SmartSolar with a battery bank underneath? Those Renogy panels are solid — how are you finding them in winter though?

I've got similar wattage split across my van and tiny house, and the seasonal variation round here is brutal. Summer I'm swimming in electrons, January I'm rationing like mad.

What battery chemistry did you go for? LiFePO4 or still lead-acid? Makes a massive difference with workshop loads if you're running tools regularly. Also curious whether you're grid-tied or completely standalone — if it's the latter, your winter strategy must be tight.

Got any photos of the monitoring setup? Always keen to see how people've configured their Victron dashboards.

Impressive build! 4kW is genuinely capable for a workshop setup. I'm curious about your battery spec — are you running lithium or lead-acid? That'll make a huge difference in how aggressively you can pull power for tools.

I've got a similar roof space on my shepherds hut (though only 2x400W Renogy) and spent ages getting the tilt angle right. South-facing at your latitude should give you cracking winter performance if you've angled it properly.

One thing I'd flag — if you're running power tools, make sure your inverter can handle the inrush current. I learned that the hard way with a circular saw. What capacity are you looking at there?

Would love to see the battery enclosure setup too. Bet you've had to think about temperature management in a shed.

@CotswoldMender and @MarshLover — fair questions. The battery spec makes or breaks a workshop setup, and I've learned that the hard way.

Four kilowatts of panel capacity is brilliant for peak generation, but you'll throttle yourself silly if the storage doesn't match your actual load profile. A mate's got a similar shed setup with undersized batteries — spends half the year watching the SmartSolar dump excess generation in summer whilst struggling to run his compressor in winter.

What matters more than raw kWh is your discharge rate. Workshop tools demand serious current spikes. A 48V LiFePO₄ bank (even modest capacity) handles that far better than lead-acid ever will, though the upfront cost stings.

@CotswoldNomad — worth posting your battery amp-hour spec and what tools you're actually running? That'll help folks calibrate realistic expectations. Victron gear's only as effective as the chemistry feeding it.

@CotswoldNomad — solid foundation there with 1.6kW nominal (accounting for real-world angle losses). The critical bit you'll discover quickly: workshop loads are bursty and unforgiving. Angle grinders, compressors, table saws — they'll hammer your battery voltage in ways a residential setup won't.

Worth asking: what's your battery chemistry and total capacity? If you've gone lithium, you've got headroom. If it's lead-acid, you'll need proper DC-DC isolation and generator backup for serious tools.

Also — and this catches everyone out — your SmartSolar will throttle input during winter. Four panels on a UK shed means November through January you're looking at 600-800W peak on a decent day. Plan your workshop schedule accordingly, or factor in grid top-up.

What's the actual load profile you're targeting?

@CotswoldNomad — looks like a proper job. Quick question though: what's your actual usable capacity on the battery bank? I'm planning something similar for a static caravan workshop and I'm realising the difference between nameplate and what you can actually draw without trashing the cells is massive.

Also, are you running the panels through a dedicated MPPT or straight to the Victron? I've got a Fogstar setup in my van and the charge controller makes a real difference in winter light, but I'm wondering if it's overkill for a fixed installation where you've got better orientation.

What sort of load profile are you seeing — is it genuinely workshop tools or more trickle charge between projects?

Been running a similar setup in a static caravan workshop for three years now, and the usable capacity question is spot on, @LisaStewart71. Most folk spec their batteries on paper then get surprised by real-world discharge curves.

I've got Victron LiFePO₄ and I'm deliberately only using about 80% of the stated capacity — keeps the cells happier long-term and you avoid that nasty voltage sag when you're actually trying to run power tools. @CotswoldNomad, if you've gone lithium, factor in that the last 10-15% becomes increasingly difficult to extract without degradation.

The Renogy panels paired with a decent MPPT controller should give you reasonable harvest through autumn/winter, but honestly, for a workshop setup, that battery bank is your lifeline. What chemistry have you gone with?

Usable capacity's the thing nobody talks about until they're six months in and wondering why the system cuts out at 20% SOC. On my narrowboat setup I've got a 10kWh bank but only cycle between 10-90% — that's 8kWh working space, which is plenty for what I need but it took me a frustrating week of tinkering to get the Victron parameters right.

@LisaStewart71 — if you're running LiFePO4, you'll want headroom both ends. Lithium doesn't mind deep cycles like lead-acid does, but the BMS gets cranky if you're constantly maxing out or draining to zero. What chemistry are you using?

The other thing worth mentioning: @CotswoldNomad, if you're doing actual workshop stuff — tools, compressors, that sort of thing — you'll be surprised how quickly your margins vanish on cloudy days. I've learned the hard way that nominal capacity is a theoretical number. Real winter days at your latitude? You're probably looking at 30-40% of summer output depending on the

@CotswoldNomad lovely setup mate. The usable capacity question is crucial — I learned this the hard way in my narrowboat days.

Most people spec a 200Ah battery bank and assume they've got 200Ah to play with. Reality check: you want to keep your lithium above 10% and below 90% for longevity, which immediately cuts your usable window to 160Ah. If you're running lead-acid (cheaper upfront), you're looking at maybe 50% usable without killing the batteries in a couple of years.

I see you've got the Victron setup, which means you can actually see what's happening via the app — that's a massive advantage. Set your discharge limit sensibly in the BMS settings and you won't get nasty surprises mid-project.

The real tell is what's drawing power in your shed. Running power tools constantly? You'll burn through usable capacity faster than you'd think, especially in winter when panel output drops. I moved from a 10kWh bank (looked impressive) down to 6kWh, but with proper discharge limits and realistic

Got to ask though — what's your battery chemistry and how are you managing the depth of discharge? @HeathGazer's spot on about nobody mentioning this until you're in the thick of it.

I'm running LiFePO4 in my boat setup and realised fairly quickly that the usable capacity versus nameplate capacity is a completely different conversation. With lithium you can theoretically go deeper, but I've still got mine configured for 80-90% DoD just to be safe long-term.

Curious whether you've gone lead-acid or lithium in the shed? The load profile in a workshop is quite different from living space — if you're running power tools regularly, that's peak draw management rather than steady baseload. Are you planning to run everything off-grid or is it hybrid with grid backup for the heavy stuff?

Also — and this might be daft — but have you factored in seasonal variation? December through February is rough for solar on the south coast, and I imagine Cotswolds isn't much better. Wondering if your 1.6kWh usable is actually going to feel like less come winter.

@HeathGazer's absolutely right about usable capacity — it's the metric that actually matters but barely gets mentioned in the specs sheets. I made this mistake on my initial narrowboat setup and spent a frustrated winter running a 10kWh LiFePO4 bank that was effectively delivering about 7kWh usable because I was paranoid about letting it drop below 20%.

The chemistry really does dictate your approach. LiFePO4 can comfortably sit at 0% without damage, so you're working with the full nominal capacity. Lead-acid, conversely, starts degrading rapidly below 50% discharge — you're looking at maybe 40-50% usable from a 400Ah bank depending on your abuse tolerance.

What's critical is matching your battery chemistry to your usage pattern and solar generation profile. A shed workshop is actually ideal because you've got daytime load flexibility — run the circular saw when the sun's up, charge tools during peak generation. That's where you see the real efficiency gains.

@CotswoldNomad, what's your anticipated winter draw versus summer generation? That differential determines whether 10k

The usable capacity point is spot on, and it's where a lot of people come unstuck. On my garden office setup, I've got 10kWh of lithium (Victron LiFePO₄ batteries) but I'm only cycling between 10-90% — that's roughly 8kWh usable, which is what actually matters for daily operations.

The math changes entirely depending on your chemistry. Lead-acid? You're looking at 50% DoD realistically if you want decent cycle life. LiFePO₄ handles deeper cycles, but you still want headroom for peak loads and charging inefficiencies. Gel batteries sit somewhere in the middle.

What caught me out initially was thinking my 10kWh bank gave me 10kWh of usable energy. It doesn't. Factor in the BMS cutoff limits, the charging losses through the Victron MPPT, inverter efficiency — you're probably working with 70-80% of nominal capacity in real terms.

@CotswoldNomad — what chemistry are you running? That'll determine whether your bank is genuinely sized right

Worth asking what battery chemistry you've gone with @CotswoldNomad — that'll dictate your DoD strategy pretty heavily. I'm running LiFePO₄ in my static caravan setup and can comfortably hit 80-90% DoD, whereas with lead-acid you're looking at 50% if you want decent longevity.

The usable capacity thing @CamperClive and others have flagged is dead right though. I made that mistake initially — looked at my total 10kWh bank and thought I had bags of headroom. Reality was closer to 6-7kWh usable depending on the season and how conservative I wanted to be with the Victron settings.

What's your actual daily usage looking like? That'll tell you whether the Renogy array is properly matched or if you're relying heavily on the grid tie-in. With a workshop setup you're probably pulling decent daytime loads at least, so the 1.6kW peak should shift something.

The usable capacity chat is dead right, but I'd also push back slightly on treating DoD as this fixed rule. Chemistry matters, yeah, but so does what you're actually powering.

I've got a static caravan setup with LiFePO₄ and I run it differently depending on the season. Winter when the panels are weak? I'm cycling deeper because I need the reliability. Summer when I'm pulling decent charge? I back off and keep it at 80% because I can afford to be conservative.

The thing that caught me out initially was confusing "what the battery can do" with "what makes sense for your use case." A shed workshop doing power tools is totally different from trickle-charging a leisure battery.

@CotswoldNomad — what's your actual load profile like? That'll tell you more than any generalised DoD recommendation. And fair play getting the photos sorted, the weather's been brutal for getting anything done properly.

The DoD conversation is crucial, but I'd add that your actual usable capacity depends heavily on how aggressively your BMS is configured. I'm running LiFePO4 in my setup and Victron's firmware allows you to set the minimum voltage cut-off pretty precisely — I've got mine at 10% DoD rather than the conservative factory defaults, which nets me an extra 900Wh of usable juice without degrading the cells noticeably over the past two years.

Worth noting that if you're on lithium, you can push closer to the theoretical maximum, but lead-acid (especially flooded types) absolutely will sulphate if you're regularly hitting 50%+ DoD. Gel and AGM sit somewhere in the middle — more forgiving than flooded, but not bulletproof.

@CotswoldNomad — what's your actual load profile like in the workshop? That'll matter more than the DoD "rules" because a steady 500W draw over eight hours behaves completely differently from spike loads. The former lets you size usable capacity tighter; the latter means you need headroom for voltage s