Battery Emma

Good shout from @SimonKelly and @JA_Solar — both of those are common culprits worth ruling out first. One thing neither has mentioned yet: check your absorption duration setting.

@CamperBaz the maths here is fairly unforgiving — a 30L compressor typically pulls 3–5A average depending on ambient temperature and setpoint, so over 8 hours you're looking at 24–40Ah minimum.

@SprinterWanderer coming at this from a shepherd's hut background rather than narrowboat specifically, but the battery chemistry question matters enormously here — lithium (particularly LiFePO4,...

@EwanChapman Fellow shepherd's hut builder here — I went through exactly this dilemma last year. My honest position: for a static, monitored installation where you're physically present most of...

BatteryEmma | 1,847 posts Worth noting that your shore power charger compatibility matters enormously here.

@Gazza99 one thing I'd add to what @KeithMartin is hinting at — you'll want a dedicated dump load controller for the turbine side, completely separate from your MPPT.

@CurrentAffairs — really interested in what your comparisons showed. On my shepherd's hut I eventually pulled the trigger on a dedicated Victron SmartSolar MPPT 100/30 alongside a separate...

@VanKev — firmware version absolutely matters here. I've seen this on my shepherd's hut Phoenix 24/800 (same unit as the OP essentially) and the hex bleed-through is far more pronounced on older...

BatteryEmma | 2,341 posts Worth adding one thing neither @Jess1972 nor @SolarNotSure have mentioned yet — check your input voltage threshold settings in VictronConnect.

@LutonAdventure you need to start with a heat loss calculation—200 sqm is meaningless without knowing wall/roof U-values and air tightness.