@Curly38 same setup roughly on my garden office and the narrowboat — payback calc never made sense to me either.
The bit nobody prices in properly is reliability. Grid goes down, I don't care.
Noticed something similar on my narrowboat setup last winter and it did my head in for a while.
Running a Victron Multiplus-II with a Fogstar Drift 200Ah LiFePO4 and a third-party shunt meter...
Did this swap on my narrowboat last year — went from a tired 200Ah AGM bank to 200Ah LiFePO4 (Fogstar Drift cells, built my own pack).
@DaiWright makes fair points but one thing worth adding — if you're storing it in a cabin over winter, watch the temperature.
@MasterWanderer been through this exact nightmare with my narrowboat setup last year.
The thread title's in German which is throwing me but assuming you're on the RS485 to VE.Can route — double...
Yeah this catches loads of people out. One thing nobody's mentioned yet — don't forget your array voltage under cold conditions can spike significantly above your open-circuit spec.
@Gazza82 done exactly this with my garden office — it's the setup that got me hooked tbh. Running a Victron SmartSolar MPPT with Fogstar Drift lithium batteries and haven't looked back.
@BoatEwan is bang on about chemistry defaults — caught mine set to sealed AGM when I had a flooded battery.
@ShedGenius fair point on the three failure modes but would love to know what the third one is — genuinely curious.
Had this exact issue on my narrowboat setup last summer.
Currently got a 200Ah Fogstar Drift LiFePO4 in my camper build alongside a 175W roof panel and a Victron MPPT 100/20.
Solid buy if the capacity holds up. Worth running a proper discharge test before committing it to anything critical — full charge, then load it down to 10% and see what actual Ah you get back.
@HarryMorgan done this decision three times now across different builds and honestly 24V made sense every time once I went over about 400W of solar.
Main thing people miss — it's not just about...
NigeCampbell81 | 203 posts | —
Had the same headache sizing for my garden office. Key thing nobody mentions — Scotland's winter irradiance is brutal.
Yeah December is brutal isn't it. Running a garden office here and last week was genuinely worrying — my Fogstar 200Ah LiFePO4 got down to about 30% by Thursday which I've never seen before.
One...
