@SolarNotSure done exactly the same on my shepherd's hut build. Went 16mm² for the battery-to-busbar run even though 10mm² would've technically "passed" — voltage drop at peak draw was...
@Bazza had exactly this on my static caravan setup. The Daly SOC is basically just a voltage-based guess, which is pretty meaningless on LiFePO4 given how flat the discharge curve is.
The BMV-712...
Ben1968 | 134 posts
@LisaStewart71 100% this. My shepherd's hut was an oven until I sorted the glazing situation.
Worth adding — have you actually load tested the battery itself? Solar and controller can be perfect but if the battery's knackered internally it'll show full voltage sitting idle then collapse...
@HeatherSoul same boat here — got a static and a shepherd's hut I'm trying to sort power for. The static I'm less worried about space but the hut is tight.
Been looking at Leaf modules myself but...
Ben1968 | 87 posts | 🏕️ Static & Shepherds Hut
Not on a narrowboat myself but had nearly identical headaches with tank sensors on my static caravan setup.
Had this exact issue in my static caravan setup last summer. Ended up being a dodgy cell interconnect — looked fine visually but had just enough resistance to cause a voltage drop under load that...
Mate of mine is thinking about converting his narrowboat to a more permanent off-grid setup, similar to what I've done with my shepherd's hut.
Same here @Gill1982 — shepherd's hut and static both running Cerbo GX. Mixed chemistry is genuinely more trouble than it's worth in my experience.
Seen this exact thing on my shepherd's hut setup. Nine times out of ten it's the Bluetooth dropping rather than anything wrong with the MPPT itself.
Few things worth trying:
Force close...
in Q&A
3 months ago
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@SolarJulie good shout on the headaches side of things. One thing I'd add from my static caravan setup — make sure your negative bus bar is properly rated before you start routing everything...
@LDVCamper good shout on the surge currents - caught me out on my static. I'd gone with what I thought was plenty of cable and then watched the voltage sag badly on startup loads.
With 48v systems...
Got a compact washer in my shepherds hut setup—game changer. Skip the full-size machines, honestly. Even with decent solar, you're fighting inrush current and battery drain.
in Q&A
10 months ago
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