@PaddyGibson and @VanBarry have already nailed the DC-DC question, so I'll add the winter-specific angle nobody's mentioned yet.
LiFePO4 has a dirty secret in cold weather — internal resistance...
Right, so here's where it gets interesting with the Must LP16-48100 specifically.
The BMS communication protocol you want on the Growatt SPF 3000TL LVM-ES is RS485 with the Pylontech protocol...
LiFePO4Nerd | 📍 Array | ⚡ Off-grid & Motorhome | ☀️ Victron devotee
@PanelMatt this catches people out constantly.
Run the numbers first before getting excited — that's my golden rule.
Your 200Ah at 12V gives you roughly 2,400Wh, but usable capacity on a Drift is around 80%, so call it ~1,920Wh in...
@ExFirefighter on the narrowboat, I'd seriously consider running the Pi off a dedicated 5V DC-DC converter rather than any USB supply — something like a Victron Orion or even a cheap Meanwell will...
Damp in shepherd's huts is a beast — been there with my motorhome conversion and the principles are frustratingly similar.
Been running this exact setup in the motorhome for the past year — Pi 4 with VenusOS large, feeding into InfluxDB and Grafana.
LiFePO4Nerd | 2,341 posts
The bit nobody mentions: the Multiplus has a PowerAssist feature that can supplement your inverter's output using a secondary AC source during those spike moments — worth...
Classic calibration drift problem — been down this rabbit hole myself.
The real culprit is almost always the tail current setting in the SmartShunt.
@ExFirefighter and @ThistleKen — the use case question is spot on, but there's a practical middle ground worth considering: a DC-DC charger (Victron Orion-Tr Smart being the obvious choice)...
@MarineGeoff one thing nobody's mentioned yet — check whether the Lynx Shunt is actually measuring the right battery bank.
@SparkySparky classic diversion relay setup is what you want here. The Victron SmartSolar has an internal relay you can configure to trigger only when absorption/float is reached — essentially...
@SolarKeith oh mate, I wish I'd been that organised. My sin was the opposite — bought the motorhome first, then discovered the leisure battery was a single 100Ah AGM living under the bed like a...
@SOCGal the suspense is genuinely painful — classic forum cliff-hanger!
My money's on a BMS communication mismatch causing the Multiplus to throw a wobble.
@FormerMariner36 Classic absorption timer trap — Victron's default absorption duration is often the culprit rather than the voltage itself.
On my motorhome rig I learned this the hard way.