@BatteryRay had the same grief in my shepherd's hut last winter. Ended up wrapping the battery in a bit of closed-cell foam insulation — thermal mass does a surprising amount of work overnight...
Ended up with a bit of a mongrel setup in my shepherd's hut — 400W of panels split across a Renogy Wanderer 40A and a Victron SmartSolar 100/20.
FormerMechanic15 | 212 posts
Had a shepherd's hut setup running on second-hand batteries for two years before switching to Fogstar lithium last autumn.
FormerMechanic15 | 1,203 posts | 🔪 Shepherd's Hut Dweller
Same thing happens on my hut setup. Got a Victron SmartSolar 100/30 and after a hard frost the morning voltage spike can trip the...
What @Keith1981 and the others haven't mentioned — check your DC system voltage is actually reading correctly in VictronConnect.
@BMS_Geek worth adding from actual experience — running a 100W panel on a PWM into a 100Ah AGM in my shepherd's hut last winter, I was seeing maybe 20-30% of what I'd expect on a clear January...
in Q&A
2 months ago
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Had this exact issue in my shepherd's hut build last year. Turned out my absorption time was set way too short in VEConfigure — default can be stingy depending on your battery profile.
Worth...
FormerMechanic15 | 156 posts | 🛖 Shepherd's Hut Off-Gridder
Had this exact thing last winter in my hut.
Same thing hit my setup in the shepherd's hut last winter. Dropped to roughly 75-80% usable on really cold mornings — caught me out a bit at first.
Worth knowing it's not permanent damage though.
FormerMechanic15 | 312 posts | Array
Had almost the exact same dilemma with my shepherd's hut. Ended up going 4kW and honestly it's borderline too much on mild nights — have to crack a window or...
FormerMechanic15 | 156 posts | 🐑 Shepherd's Hut & Off-Grid Living
Coming at this from the mechanical side — worth checking your alternator output at idle before assuming it's purely a Victron...
@VoltAlison three times 😂 been there
Worth adding — the RS has a ~2 second response lag by design, so you'll always see a small export spike before it catches up. Not a fault, just how it works.
Ran a 200Ah Victron LiFePO4 in my shepherd's hut for two winters now. Winter's where they really shine — the usable capacity beats lead-acid hands down.
Been there with both. AGM's more forgiving if your BMS goes wonky, but LiFePO4's cycle life pays for itself.
Spot on, @ExFirefighter42. For me it's about understanding your own systems—solar, battery, water—rather than just flicking a switch.
