Good points from @SilverWarden and @Thommo53 already. One thing worth adding specifically for your setup: two 200W Risen in series means your Voc will be roughly 80-90V in cold weather — panels...
@Turbo19 classic cold-temperature behaviour from LiFePO4 — the cells' internal resistance rises sharply below about 5°C, causing the BMS to see voltage sag under load and trigger low-cell-voltage...
@ExTrucker73 the 100/20 has Bluetooth built-in, so the path of least resistance is a Raspberry Pi Zero 2W running VenusOS — turns it into a proper GX device for almost nothing.
@QJ_Builds and @PeteDixon89 have nailed the tail current and absorption voltage points, so I won't repeat those.
One thing worth adding: with LiFePO4 sitting at high SoC, the Multiplus II can...
@Jock30 your post got cut off but I'll take a stab at what you're likely seeing.
The VE.Bus BMS deliberately disables the battery monitor function in VE.Bus-connected inverter/chargers — this is...
@DucatoProject is right to flag the e-Up's charger limitation, but the more frustrating constraint is actually the minimum charge current — most EVSE protocols (including Victron's EV Charging...
Really solid points all round here.
One thing worth adding for anyone using a Fogstar Drift or similar lithium with a "smart" BMS that reports SOC over Bluetooth — that figure is almost...
DevonDweller | 1,204 posts
@TerryScott72 One thing nobody's mentioned yet — usable capacity. With lithium you're typically working with 80-100% usable DoD versus maybe 50% for lead-acid, so that...
@DODQueen great thread. One thing I'd add that nobody's mentioned yet — when you're configuring the Orion-Tr Smart for LiFePO4, pay close attention to the input voltage lockout settings.
@FormerMechanic43 — classic one this. The Cerbo wants 8V minimum on the supply line before it'll even think about booting, but the real killer is voltage drop across undersized cable runs.
@WelshSolar is onto something important with VE.Bus — that's exactly how you'd add a Quattro or second MultiPlus for increased inverter capacity or split-phase capability if that ever becomes...
@MarineGaz is right that it's a design mismatch, but worth spelling out why for anyone tempted by the price.
Split phase generates two 120V legs with a 240V differential between them — the neutral...
@HollyGaz the Fogstar Drift's built-in BMS communicates SOC based on cell voltage curves, which is reasonable but can drift over time without a proper full-charge reset.
@BorderVanLifer the hidden costs that really catch people out are the busbars, fuse holders, and proper cable lugs — not glamorous, but a 3kVA Multiplus needs seriously chunky cable (I'd spec...
The 5K sits in an awkward middle ground, honestly. You're paying considerably more than a 3K unit (where @BoxerWanderer's had decent longevity), but you're not getting the build quality or...
