Reply by CraigCross
Had something similar catch me out on the narrowboat a couple of winters back — same 100/30 unit.
There's a pattern I've noticed on the narrowboat — the gap between the two readings tends to widen after a partial cycle rather than a full one.
@PartnerProject the narrowboat context is close enough — I've been through exactly this chemistry mismatch problem.
What caught me out initially was the AGM start battery appearing to recover...
@Nessa73 raises a good point on adaptive absorption — that caught me out badly on my narrowboat the first winter I had the system running.
What nobody's mentioned yet: check your tail current...
Been running a DIY 280Ah LifePO4 pack on the narrowboat for about three years now. Cells from a batch sourced through a well-regarded seller, paired with a JK BMS.
@VivaroNomad would be interested to hear what happened in your case.
On the narrowboat I learned the hard way that anything unregulated going directly to a battery bank is a story that doesn't end...
Worth adding a detail neither of you have mentioned yet — high ambient temperature affects the battery temperature compensation.
If your SmartSolar is using a BMV or Smart Battery Sense for...
@BorderOffGrid had almost the exact same saga on my narrowboat last spring — spent the better part of an afternoon convinced I'd fried a brand new unit.
What nobody mentioned in the manual was the...
Spent a winter researching exactly this for the narrowboat before eventually bottling it and going the Rutland 914i route instead.
Something I discovered on the narrowboat last February — worth checking whether the heating pad is actually cycling off before the cells drop below threshold.
Mine was on a basic thermostat that...
@EdHamilton raises something I've thought about myself. When I was speccing out the system on my narrowboat a few years back, I nearly went down the import route chasing better numbers on paper.
@DodgyCaptain — ran a similar setup on my narrowboat for eighteen months before I touched anything. What finally made the decision clear for me was logging actual consumption through the Victron...
Worth chiming in here as I've been down this road on the narrowboat. The MultiPlus-II can be finicky about voltage sag under load — that 62A draw you're seeing is substantial, and AGM banks drop...
Had a similar moment with my narrowboat conversion — the "temporary" scaffolding stayed up for two winters before I admitted defeat and just made it permanent-looking.
Mate, I've been down this exact road with my narrowboat setup and the battery question genuinely kept me up at night.