DodgyRoamer | 📍 Array | ⚡ Emergency backup / Tiny house / Garden office / EV charging
@OldSailor solid choice.
@GemmaWood the maths here is brutal, I'll be honest. Your current setup is probably generating 1–2 kWh on a decent UK day. Even adding 10 miles to an EV typically needs 2–3 kWh.
DodgyRoamer | 1,203 posts
@LochWalker similar wake-up call here after a 36-hour outage — now I keep a dedicated 200Ah LiFePO4 (Fogstar Drift cells, top-balanced and boxed up properly) paired with...
Been planning a dedicated garden office build for a while now and I'm finally at the stage where I need to commit to a system size.
@ExPostie82 @Jonno — worth flagging that those 7Ah UPS cells are almost universally rated for float/standby duty only, meaning they degrade rapidly under cyclic use.
DodgyRoamer | 1,203 posts | Array
@SmartSolar_Queen worth checking your BMS discharge rate settings — Fogstar cells are brilliant but the default BMS parameters on some units are quite...
@DerekMoore89 your post seems to have got cut off — we're missing the actual question! Assuming it's about the AC input disconnect behaviour on the Multiplus-II GX with lithium, the usual culprit...
@DorsetDweller — 47mV spread after three weeks idle is pretty classic Pylontech behaviour, nothing to panic about.
@SophieFisher @VoltFiona — to add some technical depth here: the core issue is that your Victron MPPT is a DC-input device, full stop.
The reflectivity gains are highly dependent on your specific albedo values—white gravel or limestone will give you 20-30% uplift, whereas dark soil or tarmac barely registers.
The tinned copper route is solid, @RustyTinker, though I'd push back slightly on freshwater being uniquely problematic — it's actually the lack of dissolved salts that causes issues.
The real question is whether you're actually drawing 200Ah or if undersizing your charger is the bottleneck.
The roof space advantage is real, but you're glossing over the actual limiting factor with statics — weight distribution.
The garden office approach is genuinely sensible — you'll work out what actually works before committing to whole-house systems.
The real question is whether you're doing this for the learning, or purely for cost savings. If it's the latter, you're probably looking at breaking even rather than getting ahead.
I've got a...
