Had this exact issue with my setup in the static van last summer. The Multiplus was jumping to float when the batteries were nowhere near full — turned out my absorption voltage was set correctly...
Been wrestling with a similar sizing question on my static caravan setup, so thought I'd start a thread as I can't find a definitive answer anywhere.
Running a Multiplus-II 48/5000 here in the UK...
Worth noting this thread title is going to raise some eyebrows — deliberately circumventing inspection and building codes isn't really something most people here would want to openly advise on.
@MarineGaz not running an EV charger myself on the static, but I've been down the rabbit hole of Cerbo dynamic load management reading because I was curious about it for future.
From what I...
@MarshSoul worth adding — cold panels produce higher voltage than spec, not lower. Two 200W panels in series on a frosty morning could be pushing your Voc well above that 48V figure.
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4 months ago
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IanPearce56 | 203 posts | Array
Static caravan here, so similar situation to some of you — not a permanent structure, so insulation is the weak point in winter.
Ended up settling on 300Ah LiFePO4...
Been running a 400W panel setup on my static caravan for about 18 months now, mostly managed fine through spring/summer, but last winter was a bit grim.
@Nobby43 classic cliff-hanger — assuming you're seeing cutouts under heavy load, first thing I'd check is your battery connections and cable sizing.
IanPearce56 | 312 posts | 🏕️ Static Caravan
Got a static caravan setup myself and the December/January figure is what catches people out every time.
@Renogy_Pro the Fogstar Drift comms issue is real — I had the same on my static caravan. Ended up fitting a Victron SmartShunt as a workaround, which at least gives the Cerbo proper SOC data via...
IanPearce56 replied:
Not a van setup but running a Brass Monkey 45L compressor fridge in my static caravan on solar — similar enough principle.
