Victron Multiplus 2000 keeps dropping to float too early — anyone else had this?

Running a 200Ah Fogstar Drift LiFePO4 on my shepherd's hut build, paired with a Victron Multiplus 2000VA/80A and a SmartSolar 100/20. The problem I'm seeing is the Multiplus keeps transitioning from bulk/absorb into float way before the battery's actually full — we're talking 85-90% SoC according to the BMS app, but the charger's convinced it's done. Annoying as anything when you've got a cloudy week ahead and need every amp in the bank.

I've gone through VE.Configure and the absorption voltage is set correctly at 14.2V for LFP, absorption time on "adaptive" with a tail current of 4A. My suspicion is the adaptive absorption algorithm is being too clever for its own good — it's learned a short absorption time from previous cycles and is cutting out early. Might need to switch to a fixed absorption time of around 2 hours and see if that sorts it.

Has anyone else hit this with a Multiplus + LFP combo? Particularly curious whether the issue is in the charger settings, something the BMS is doing over the VE.Bus Smart Dongle, or whether the Fogstar BMS is sending a premature "charge complete" signal. I don't have DVCC enabled at the moment so I'd have ruled that out, but stranger things have happened.

Any VE.Configure screenshots or working LFP profiles people are happy to share would be genuinely useful rather than the usual copy-paste-from-Victron-docs answers.

Mine did the same in my garden office setup — turned out the absorption time in VictronConnect was set embarrassingly short, basically treating the battery like it had already done its cardio when it hadn't even left the sofa.

Check your Battery Monitor settings too — if the Multiplus and SmartSolar aren't talking to each other properly via VE.Smart networking, they're each making independent (and wrong) decisions about State of Charge. Two devices arguing about the same battery is never a good look.

Also worth double-checking your tail current threshold in the charger settings — Fogstar Drift cells are quite efficient so the charge current drops off fast, which can fool a poorly calibrated system into thinking absorption is done prematurely.

Hey @SolarJunkie, worth checking your tail current setting in VEConfigure as well — this is often the culprit that gets overlooked. On LiFePO4, the battery transitions to float once the charge current drops to a certain percentage of capacity, and if that threshold is set too high it'll cut absorption short thinking the battery's full when it isn't. For a 200Ah Fogstar Drift I'd suggest setting tail current around 1-2% (roughly 2-4A). Also double-check your battery capacity figure is entered correctly in VEConfigure, as it feeds directly into that calculation. @QuietHiker makes a fair point about absorption time too, but the tail current issue catches a lot of people out, especially on newer LiFePO4 installs where the default settings are still calibrated around AGM assumptions.

Had exactly this on my boat last season. Check your battery capacity setting in VEConfigure — if it's set too low, the Multiplus calculates absorption time from that figure and cuts out way before the cells are actually full.

Also worth connecting a battery monitor (I use a Victron BMV-712) to see what the actual SoC is when it drops to float. Mine was showing 78% when the Multiplus thought it was done 🙄

One more thing — make sure the Multiplus and SmartSolar are networked via VE.Smart so they're sharing battery voltage readings. Without that they're essentially working blind off each other.

Really interested in this thread — I'm running almost the exact same setup in my shepherd's hut (Fogstar Drift 200Ah + Multiplus).

One thing nobody's mentioned yet: have you checked whether your battery temperature is feeding into the Multiplus correctly? If you're not using a BMV-712 or Smart Battery Sense, the Multiplus may be compensating for temperature it's guessing wrong, which can affect charge termination behaviour.

Also worth asking — are you on shore power or solar only when this happens? I've noticed my system behaves differently depending on the charge source, and it helped me narrow down whether the issue was in VEConfigure settings or the MPPT profile.

Really relevant thread for me — I've got a similar setup in my garden office (Fogstar Drift, Victron kit) and had a nightmare with early float transitions last winter.

One thing nobody's mentioned yet: are you running ESS or a standalone charge profile? I found that when I accidentally had ESS Assistant loaded in VEConfigure it was completely overriding my absorption settings in ways that made no sense. Stripped it back to no assistant and the behaviour became much more predictable.

Also worth checking — is your SmartSolar networked to the Multiplus via VE.Smart or VE.Direct? If the MPPT isn't sharing battery voltage data properly, the Multiplus might be seeing slightly different voltage readings and making poor decisions about when to transition. Victron's own documentation on networked charging is genuinely worth a read before diving too deep into individual settings.