Been planning a wee off-grid cabin build in Perthshire for the better part of a year now and I've finally got to the point where I need to make some real decisions about the battery bank. The cabin will be used year-round, maybe 3–4 days a week on average, and I'm budgeting for roughly 2–3 kWh of daily consumption — LED lighting, a 12V compressor fridge, laptop charging, and a small inverter for occasional power tools.
The obvious headache is the Scottish winter. I'm looking at potentially 4–5 hours of usable solar in summer dropping to under 1 hour in December, so I know I can't rely purely on PV. I've got a 2kW wood gasifier stove on the cards anyway, and I'm wondering whether a small DC generator for top-up charging makes more sense than massively oversizing the battery bank to cover a run of cloudy days.
Currently I'm torn between going with lithium (LiFePO4) at maybe 10kWh and keeping the bank manageable, versus a larger AGM setup which would be cheaper upfront but obviously heavier and less efficient in the cold. Has anyone actually run a cabin setup through a full Scottish winter and got real data on what the batteries actually did? Discharge curves, how often the genny kicked in, that sort of thing — proper numbers would be gold right now.