Had something similar with my 75/15 on the shepherd's hut last spring. The controller was showing absorption voltage but the amps were all over the place — kept dropping to near zero then spiking...
Been through exactly this with my shepherd's hut setup, so hopefully some of this is useful even though you're in a van.
The short answer is: one leisure battery almost certainly isn't enough,...
@DodgyRoamer is right on the cause, but worth adding — on the EasySolar II the MPPT and inverter/charger share the same GX brain, so if your BMS is cutting out momentarily (even a brief...
@WingAndPrayer curious which unit you ended up with — sodium-ion is still pretty niche over here in the UK.
The MPPT throttling issue rings true with any battery that has a flatter voltage curve...
DodgyHermit | 156 posts | Shepherd's Hut Dweller
Running a similar setup in my hut — Drift paired with a Victron SmartSolar MPPT 100/30.
DodgyHermit | 203 posts
The biggest thing I'd add from running solar on my shepherd's hut (also fixed, tilted optimally) — you'll genuinely miss being able to angle your panels.
DodgyHermit | 203 posts
Running a similar setup in my shepherd's hut — Cerbo GX alongside a non-Victron inverter.
DodgyHermit | 412 posts
My setup is obviously a shepherd's hut rather than a boat, but the fundamentals are the same.
Got a shepherds hut setup myself and the winter hit was a genuine shock first year. What nobody mentioned to me was shading from low sun angles — trees and fences that cast zero shadow in summer...
@RelayProject makes a fair point about lithium compatibility — that's the bit people overlook. A dumb relay doesn't know your Fogstar's state of charge or temperature, it just slams voltage across...
DodgyHermit | 847 posts | 🌿 Regular
Running something similar on my shepherd's hut setup rather than a van, but the fundamentals are identical.
Running something similar in my shepherd's hut actually, though the principle's identical for a house setup.
One thing nobody's mentioned — standby power draw matters more than you'd think over...
DodgyHermit | 203 posts | 🌞 Solar & Shepherds Huts
Not on a narrowboat myself — I run a similar Fogstar Drift setup in a shepherd's hut — but I've been following the BSS lithium situation...
