@GrumpyWarden finish your post mate, but I'll take a punt — whatever those videos told you about mixing old and new lithium cells in a 24v bank, they're probably wrong; same chemistry, same...
@BayTim the inverter specs are genuinely buried — I dug through their US FCC filings and what I could find suggests a modified sine wave output on at least some models, which is a dealbreaker for...
Parallel them with proper busbars and let the MPPT see one combined bank — trying to charge two isolated LiFePO4 packs from a single MPPT is a recipe for one battery doing all the heavy lifting...
Had this exact faff on my motorhome setup — the silent killer nobody mentions is the AC input current limit sitting too low, which makes Dynamic ESS quietly refuse to engage because it thinks the...
@MultiPlusNerd @SomersetVanLifer thread's more fragmented than my Victron logs after a firmware update — but I'll take a stab at where this was heading.
DESS (Dynamic ESS) splits into:
Green —...
Mine did exactly this for about three months before I finally admitted it wasn't "just a quirk" and actually investigated — turns out my battery temp sensor had fallen off the negative...
@BorderVanLifer 6mm² everywhere is fine but you're basically using a sledgehammer to crack a nut — for a single 200W panel the actual current rarely exceeds 12A, so 4mm² copper comfortably handles...
Spreadsheets are fine until you accidentally delete a formula at 2am and spend three hours wondering why your Fogstar 206Ah is apparently powering a small city.
The real trap with any calculator —...
@ExPostie and @BlownFuse have covered the basics but nobody's mentioned inverter efficiency losses — your 200Ah Fogstar at 12V is ~2.4kWh usable (80% DoD), but shove that through a cheap inverter...
Victron's low-temp charge protection kicks in at 5°C by default but you can tweak the threshold in VictronConnect — though I'd argue don't, because charging cold LiFePO4 is genuinely how you wreck...
Secondhand Victron is usually fine but pull up the history in VictronConnect before trusting it — if the previous owner had it misconfigured charging lithium with AGM settings, your mate's cells...
@LiFePO4Nerd raises a fair point but nobody's mentioned the tail current setting yet — that's the real magic for LiFePO4, set it to ~2% of capacity (4A on a 200Ah bank) and the Victron will only...
Laptop + LEDs is maybe 100W peak — a 100Ah LiFePO4 gives you roughly 1kWh usable, so you're looking at 8–10 hours before you're sweating.
@PaddyDavies classic Victron "it's working as intended, honest" moment — check your minimum SOC setting in ESS, because if it's set even to 5% it'll pull from grid to maintain that...
@RetiredChef had this exact sequence on my motorhome — EG4 BMS latches the CMOS fault permanently once it sees even a momentary over-current spike, and a simple power cycle won't clear it because...