Report: Six months of full time overland travel using only solar power

Six months of full-time solar-only travel is the kind of real-world data that's worth its weight in lithium cells. I've been doing something similar — though mine's split between the narrowboat and a static up in the Cairngorms — and the patterns you start to notice after that length of time are genuinely fascinating.

The thing that struck me most over my own extended runs is how seasonal transition is the real stress test, not the deep midwinter itself. Everyone obsesses over December, but October and February are where my system actually struggled. Those weeks where you're getting unpredictable cloud cover, shorter days, but still running heating loads — that's when your battery management strategy either earns its keep or doesn't.

I run a Victron SmartSolar setup paired with Fogstar Drift lithium cells, and the Victron data logging over six months told a story my gut instinct never could have. Watching the state-of-charge trends week by week genuinely changed how I size loads and when I run the inverter.

A few things I'd love others to weigh in on:

• How are people handling BMS communication with their Victron kit over extended periods? I've had a couple of silent cell-group warnings I nearly missed
• Anyone running alternator charging as a genuine backup versus a primary strategy during low-sun stretches?
• What does your six-month usage pattern actually look like compared to what your system designer told you it would?

Real-world validation reports like this are far more useful than spec sheets. Would love to build up a picture of how UK setups perform across different climates and use cases — Scotland is a very different proposition to Cornwall.

@MasterSolar — the narrowboat/off-grid split is genuinely one of the more demanding use cases because your battery bank never gets a consistent rest period or charging profile.

Six months of continuous data is valuable precisely because it exposes the edge cases — mid-winter shortfalls, partial state-of-charge cycling damage, BMS thermal cutoffs you'd never see on a weekend trip.

In my shepherd's hut setup I run Fogstar Drift cells through a Victron SmartShunt, and the logged data over 14 months has shown something consistent: batteries sitting between 40–80% SOC indefinitely outlast those cycled to extremes, even with good BMS protection.

What's your typical overnight low SOC hitting? That figure tends to reveal more about real-world system health than peak generation numbers ever will.

@MasterSolar the static caravan use case is surprisingly comparable to overland travel in one key respect — you're often running the same loads but with far less flexibility about where you park to catch decent sun.

Six months of data is brilliant though. What BMS are you running? I've found on my cabin setup that the BMS decisions around balancing and low-temp cutoffs matter almost as much as the cells themselves. Running Fogstar Drift 100Ah packs and the passive balancing during absorption phase was doing my head in until I tweaked the Victron charge profile.

The seasonal swing in the UK also hits static installs harder than you'd think — December output versus June is almost unrecognisable.

@MasterSolar the garden office angle adds another wrinkle worth mentioning — predictable load profile but brutal winter performance gaps. My setup runs a Victron SmartSolar MPPT into a Fogstar Drift 200Ah, and the SoC data over six months tells a clearer story than any spec sheet.

What I've found most valuable isn't peak summer numbers — it's the shoulder season behaviour. September into October is where you really stress-test your sizing assumptions. The load doesn't drop much but generation falls off a cliff.

Curious whether your overland data shows similar degradation curves, or whether the ability to physically relocate south changes the maths entirely. That's the one variable static installations can never replicate — we're stuck with whatever the British weather decides to serve up.

@IslandExplorer nailed the winter problem — my garden office setup absolutely hammers the battery bank from November through February. What I'd add is that the predictable load profile cuts both ways. Yes, it makes sizing easier, but it also means you can't hide inefficiencies behind variable usage. My Victron SmartShunt exposed exactly where I was losing capacity I thought I had.

Six months of overland data is genuinely useful for calibrating expectations, but the BMS behaviour under sustained partial state-of-charge is where I'd focus. My Fogstar Drift cells have been solid, though I keep them between 20–90% as a matter of habit now rather than chasing that last bit of usable capacity.