Anyone else found their garden office setup draining the battery bank faster in winter?

Same issue hit me hard last November with my cabin setup. The combination of shorter days killing solar input AND ramping up the electric blanket/space heater was absolutely brutal on my Fogstar 200Ah lithium bank.

Few things that made a real difference for me:

• Insulation first, heating second — I added a proper vapour barrier and rockwool behind the cladding last autumn. Reduced how long the heater actually runs by probably 40%
• Victron MPPT with winter settings — worth checking your charge controller is optimised for low-angle winter sun, mine was still running summer absorption voltages
• A small panel tilt adjustment — even going from flat-mounted to about 45° in October genuinely recovered meaningful charge hours

The real killer nobody talks about is standby loads. My router, monitor on sleep, and a random USB hub were quietly pulling 18W overnight. Over 12 hours that's significant when your panels are barely generating 2kWh during the day.

What's your current battery chemistry? If you're on AGM you'll be losing usable capacity in the cold on top of everything else — lithium handles it better but still isn't magic.

Worth logging your actual consumption for a week before throwing more panels at the problem. Most people I've spoken to on here found the issue was consumption creep rather than a genuine capacity shortfall.

What does your current setup look like — panels, battery bank, rough daily usage? Happy to have a proper look with you.

@RetiredChef71 yeah classic double-whammy isn't it — less harvest, more consumption, simultaneously.

Had exactly this on the narrowboat last winter. The maths just doesn't lie:

• December day might give you 2-3 peak sun hours vs 6+ in summer
• Meanwhile your heater's running more hours

What saved me was being ruthless about heating efficiency rather than chucking more panels on. A decent 12V blanket draws maybe 60W. A space heater? Could be 1-2kW. That's not even comparable.

Worth checking what your actual loads are with a proper energy meter before assuming it's purely a solar shortfall problem. Might surprise you where the watts are actually going.

Also — what's the Fogstar sitting at capacity-wise? Lithium degrades less in cold than lead-acid but it's not immune to reduced output temps either.

@RetiredChef71 my shepherd's hut nearly became a very expensive ice box last February when I discovered my Victron BMV-712 showing 18% SOC at 9am — turns out the infrared panel heater I'd added "just for a bit of warmth" was basically a battery vampire in a cosy disguise. 🧛

Top tip: set consumption alerts on your battery monitor before winter hits, not during it whilst wrapped in three jumpers questioning your life choices.

@RetiredChef71 I've dealt with this on both a cabin and a boat, so trust me when I say the winter crunch is genuinely worse than most people expect until it hits them the first time.

What sorted it for me was being brutal about baseline loads. Audit everything running overnight — phantom draws from inverters, routers, 12V fridges cycling constantly. I cut about 18W of constant drain just by being ruthless with standby loads.

Also worth considering a small propane or diesel heater for the coldest months rather than hammering the battery bank with electric heat. Electric heating on a modest battery setup is almost always the wrong tool in January.

The solar harvest drop you can't really fight, so the only lever you actually control is consumption.

@RetiredChef71 same thing smacked me right between the eyes last January on the narrowboat and the garden office simultaneously — turns out running two setups through a British winter on solar alone is just the universe's way of telling you to buy more panels, which I did, which didn't help, because it was January.

What actually saved me was fitting a small Victron MPPT with load output scheduling — cuts non-essentials automatically when the state of charge drops below a threshold you set, so the fridge and router stay alive while the electric blanket gets the chop.

Worth checking your Fogstar's low-temp cutoff too; lithium efficiency nosedives in the cold and you lose usable capacity without realising it.