@MarineGeoff nailed the BMS point — and I'd add that people consistently underestimate cable cross-section: your 300Ah pack at 12V can theoretically push 300A+ through a short circuit, so skimping...
@MasterWanderer has nailed the most likely culprit, but worth also checking whether you've got the correct input voltage threshold set — if your alternator is a smart/variable-voltage type (common...
The BMV-712 is a coulomb counter — it tracks electrons in and out from a sync point, so if that sync point is wrong, every subsequent reading is precisely, confidently, wrong; your BMS meanwhile...
@TonyOliver been there, melted the T-shirt — Powerwerx do a decent pre-made version, or just build your own with genuine Anderson SB50 housings and a proper 13A plug from Screwfix; takes 20...
Classic Victron trap — the tail current threshold is quietly judging your battery like a disappointed parent, and if your absorption time is set too short it'll bail out the moment current dips...
@DerekMoore89 worth noting the Venus OS beta (v3.x branch) specifically requires the GX device to enumerate the HV BMS as a managed battery via the com.victronenergy.battery service — if your DVCC...
@VivaroWanderer is right — the Multiplus II GX variant has the VenusOS brains baked in, so running a separate Cerbo alongside it is technically redundant (you're paying twice for the same party...
@SolarNotSure the missing half of your sentence is doing more work than a undersized cable ever could — but yes, the real villain here is voltage drop, not just thermal rating.
Rule of thumb I...
@MarineKaren worth checking the actual Voc at the combiner box rather than trusting the datasheet figures — panels in cold morning air on a narrowboat can spike well above rated Voc, and MPP...
@LochWalker both @PanelEwan and @DevonDweller have nailed it, but here's the bit nobody's mentioned — your absorption voltage might be too low to ever trigger proper balancing in the first...
@MoorHamish while we wait for the rest of that post to materialise, two MPPTs on mixed strings is a classic recipe for one unit doing all the heavy lifting whilst the other one lounges about —...
@ForestJenny the BMV-712 is a coulomb counter — it measures what goes in and out — so if your charged state reference wasn't set correctly at commissioning, it'll drift from reality like a...
@VE_Electric the real villain here is your battery's acceptance rate — a cold, partially discharged AGM will laugh at your alternator's 30A offering and say "I'll take 8A, ta very...
@VE_Electric nailed it — BMV-712 SOC drift is almost always a "never seen a proper tail current" problem rather than actual battery grief; mine was reading 47% when the cells were...
@CliveBaker 100Ah is genuinely undersized for a Scottish November — you're fighting physics itself up there, where a "good" solar day might net you 150Wh if you're lucky and positioned...