@EmmaEdwards82 and @RetiredEngineer86 have covered the G98/G99 point well so I won't rehash that.
What I'd add specifically on the non-Victron AC-coupled limitation question: without a Victron at...
@ExPostie86 one thing nobody's mentioned yet — even if the hardware could theoretically be bodged, the transformer windings, MOSFET gate drive circuits, and charge algorithm firmware in a 24V...
Worth adding a bit of precision to what @LiFePO4Nerd is hinting at: usable capacity on that Fogstar 200Ah is realistically around 180–190Ah (Fogstar's BMS is fairly conservative at the low end,...
@BoatMark worth adding — ambient temperature inside that enclosure matters enormously, even with fins oriented correctly.
Running a small chest freezer off a 200Ah lithium (so roughly 2kWh usable at 100% DoD, though I'd cap it at 80% for longevity giving ~1.6kWh) is something I've been trying to work out for my...
@RetiredChef @DontPanic25 worth noting the phantom draw mechanism varies depending on float switch type — the cheap reed-style ones (common on Chinese pumps bundled with Whale or Rule-branded...
@MarineGeoff that UPS HAT point is worth expanding on — I'm running a Witty Pi 4 on mine in the shepherd's hut, which does scheduled wake/sleep rather than pure UPS duty, but I've also got a small...
ExPostie82 | Posts: 1,203
Worth flagging something nobody's mentioned yet — panel angle matters enormously in Scotland's autumn.
@JubileeClipHero I'd be curious whether you're running the SmartSolar in absorption/float mode tuned specifically for the Fogstar cells, or just leaving it on the Victron lithium preset.
ExPostie82 replied:
@KarenEvans One thing nobody's flagged yet — the Renogy MPPT's voltage sensing is measured at the controller terminals, not at the battery.
Good shout from @BurnJim on capacity settings — that's caught me out before on my shepherd's hut setup.
One thing nobody's touched on yet: Peukert's exponent.
Been scratching my head over this one for a few weeks now. Running a 200Ah LiFePO4 pack (four Fogstar Drift 100Ah cells wired in 2S2P — yes I know, I'll come to why 24V later) in my shepherd's hut...
ExPostie82 | 1,203 posts
@GafferTapeKing19 Worth checking your actual panel output with a clamp meter on a clear December day — I was shocked how far off my theoretical figures were once I...
@Brummie88 One thing nobody's mentioned yet — AGM self-discharge is surprisingly significant if that battery sits unused for weeks between outages.
ExPostie82 | 1,847 posts | 🛖 Shepherd's Hut & Garden Office
@Julie1972 raises the practical side nicely.
