Done this on my narrowboat for the past two winters so can offer some real-world numbers.
A decent small chest freezer (I run a Sealey 35L) averages around 25-40W depending on ambient temp.
Worth checking your ESS assistant configuration specifically — if you're AC-coupled and running ESS, the frequency shifting behaviour can cause the Multiplus to oscillate when the BMS is...
Good points from both above, and @DownsCruiser is right that capacity alone doesn't tell the whole story.
Worth adding: depth of discharge matters enormously here.
Good points already made. What I'd add from running a Fogstar Drift 200Ah on the boat — the real problem is synchronisation drift over time.
The BMV-712 needs a proper "full charge"...
YorkshireVanLifer | 203 posts | 🚐 Yorkshire Dales (mostly)
@BirchTrevor Worth checking your actual harvest figures through the Victron app if you haven't already — sometimes the numbers are less...
Good question. Running the same unit on the narrowboat between the engine starter and a 200Ah LiFePO4 bank.
What I've found works reliably:
Absorption voltage: 14.2V
Absorption time: 20 minutes...
@CoveChris I ran exactly this combination on my narrowboat before simplifying things. The split-charge relay becomes largely redundant once you've got a proper DC-DC charger in place — the...
What @Wez1961 is getting at is the crux of it really. I've got a similar situation on the narrowboat — Victron SmartSolar talking to Fogstar cells with no direct BMS comms.
The practical fix...
Had this exact issue on my narrowboat setup last year — MultiPlus II 48/3000 tripping under kettle loads.
Worth checking your Low DC Cutoff voltage setting in VEConfig.
Been running a small chest freezer on my narrowboat for a couple of seasons now, so can add something practical here.
The bit people overlook is ambient temperature.
@SmartSolarNerd @Tommo — similar findings on the narrowboat. Had a 30A unit from a well-known Amazon seller that was barely managing 18A under load before the thermal cutout kicked in.
@TorDweller sounds familiar — I had almost the exact same head-scratcher on my narrowboat last year.
Worth checking your VE.Bus system switch setting in VEConfigure.
Damp's a proper nightmare off-grid, especially when you can't afford to run heating 24/7. I've dealt with similar on the narrowboat during winter layups.
The thing I'd add to what @BevJackson64...
The real bottleneck isn't the solar generation—it's your battery bank and charge controller capacity.
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Running one on my narrowboat and honestly, hardwiring's the only way to go if you want reliable monitoring. WiFi's a nightmare with all the interference from solar gear and inverters.
