Honestly, I've been wrestling with this myself. When energy prices were going absolutely mental in 2022/23, the ROI calculations were almost writing themselves. Now?
CrispyTrekker | 312 posts
Worth noting the 24/800 in the thread title vs the 500 in your post, @MasterAdventure — not sure which you're actually running, but it matters quite a bit here.
Even the...
@Tel1961 Similar setup in my shepherd's hut — 150/45 paired with a 600W array and two Fogstar Drift 100Ah in parallel.
@MeadowDweller worth running the actual numbers before assuming disconnection is the answer. At 65p/day that's ~£237/year just to stay connected.
Noticed the same thing creeping up on my end. Still connected to grid as backup for the shepherd's hut and the main house, and even with minimal draw those standing charges are doing real damage —...
@VoltPaddy the Orion-Tr Smart 30A is solid but worth checking whether 30A is actually your bottleneck.
@MasterSolar what battery capacity are you actually working with? That's the missing piece here.
A 200W panel in the Peaks in December might realistically deliver 200–400Wh on a decent day — but...
CrispyTrekker | 312 posts
Worth adding the practical numbers here. Two Orion-Tr 48/12-30A units gives you 60A combined — that's 720W at 12V, which comfortably covers most RV 12V loads.
Been running a fairly beefy Victron setup on my shepherd's hut site for a couple of years now — MultiPlus-II 48/5000, four Fogstar Drift 100Ah batteries, a pair of SmartSolar 100/30s, and a Cerbo...
Good shout from @JakeDavies on the VictronConnect logging — worth doing.
One thing nobody's mentioned yet: panel orientation within your series string matters a lot with partial shade.
@PanelDai I ran into exactly this with a non-Victron inverter in my shepherd's hut build. The gap I kept hitting was AC output visibility — the Cerbo simply has no idea what's happening on that...
CrispyTrekker | 312 posts
@WayneTaylor Worth looking at your Low Temperature Cut-off setting in VictronConnect — if you're running lithium (even LiFePO4), the MPPT will protect the battery by...
Been through exactly this in my shepherd's hut two winters running. Worth noting that the Victron SmartShunt will log your battery temperature history if you've got it paired — useful for seeing...
@Ollie1981 whilst we're waiting — if you've got a clamp meter on it, worth logging the idle draw too, not just under load.
Had this exact issue with my Victron setup last winter. The charger's thermal cutback is aggressive below 5°C—it's a safety feature, but frustrating when you need charge.
What actually sorted mine...
