Anyone else running a woodburner alongside solar in their off-grid cabin? How are you managing the heat/battery balance in winter?

We've got a small cabin in the Scottish Borders — 16m² insulated timber frame — and we've been running a 400W solar setup (2 × 200W panels, 200Ah lithium) since last spring. Summer was brilliant, barely touched the batteries. But now we're heading into the darker months and I'm trying to figure out how much we can realistically lean on the Hobbit stove for heating versus keeping the electric draw down for lights, phone charging, a 12V pump, and occasionally a small fan to move the warm air around.

The thing I keep going back and forth on is whether it makes sense to add a thermoelectric generator (TEG) to the flue pipe to claw back a bit of charge when the stove's going. I've seen a few people mention the Tegmart units online but I've never met anyone who's actually used one in a real UK setup. The numbers I've seen bandied about — 10–20W from a decent flue temp — seem almost too modest to bother with the faff, but then again in December up here even 15W for 6 hours is something.

Has anyone actually done a winter in a similar setup? Curious what your real-world consumption looked like once you stopped relying on the panels, and whether you ended up supplementing with a small genny, a TEG, or just rationed everything down to basics.

Neil1978 | 47 posts

@CamperBaz Nice setup — Scottish Borders will definitely test your system come January! We're running something similar in Northumberland, though slightly bigger cabin.

One thing I'd flag that took me a while to figure out: your woodburner can actually help your battery situation indirectly. Once the cabin's warm enough, I shift non-essential loads (phone charging, small devices) to run off a cheap thermoelectric generator sitting on top of the stove. Nothing massive but every little helps when you're getting maybe 2-3 hours of useful solar in December.

Also worth checking your panel angle — I tilted mine steeper for winter (around 60°) and picked up a noticeable improvement over the flat summer position.

What's your main load in winter — lighting, or are you running appliances too? Makes a difference to how you'd approach the balancing act.

CoastalCamper | 203 posts

Running something similar in my van, so take this with a pinch of salt for a cabin setup — but the lesson transfers nicely.

The woodburner is your winter backup. Don't fight it, lean into it.

What I'd actually focus on is thermostat-controlled extraction — a small 12V fan triggered when the flue area gets warm enough to move heat around efficiently, rather than letting it stratify. Draws almost nothing from your 200Ah Fogstar or whatever lithium you're running.

Also worth considering: cold batteries lose capacity fast. If your battery bank is in an unheated space separate from the burner's warmth, you're losing usable capacity before you've even started. I'd prioritise locating them somewhere they benefit from ambient heat — even 10°C difference makes a meaningful impact on a cold January night in the Borders.

Charlie1981 | 312 posts

Running a 5kW Hobbit stove in my shepherd's hut alongside a Victron/Fogstar setup — the thermal mass interaction with battery management is something people overlook completely.

Key thing I've found: once the stove's going properly, your heating loads drop to near zero, which means your 200Ah isn't being hammered by a compressor heater all night. That's actually your winter saviour on short solar days.

What catches people out is condensation cycling — cold cabin, warm stove, cold again overnight. If any of your cable runs or battery terminals are near that thermal swing zone you'll get corrosion faster than expected. Worth checking connections come spring.

Also worth considering a DS18B20 temperature sensor wired into a Cerbo GX if you upgrade — lets you see battery temp vs ambient and avoid charging a cold lithium bank first thing on a frosty morning.