Batterie défaillance mppt 150/85

Had a similar situation with my Victron MPPT 150/85 about eight months back — worth sharing because it took me a frustrating week to track down the culprit.

The fault LED sequence on mine was pointing toward a battery-side issue in VictronConnect, same blinking pattern you're likely seeing. Turned out the problem wasn't the controller itself at all. I'd recently added two Fogstar Drift 200Ah LiFePO4 cells to my existing bank, and the BMS on one of them was intermittently tripping under load, presenting the MPPT with what looked like an open circuit on the battery side. The controller quite rightly threw a fault.

A few things worth checking systematically:

• Battery voltage at the MPPT terminals — not at the battery itself. Voltage drop across dodgy connections will tell you a story
• BMS communication — if you're running lithium, is the BMS actually allowing charge? Mine had a temperature cutoff triggering at low morning temps
• Absorption settings — if you've got lithium cells but the MPPT is still configured for lead-acid absorption voltages, some BMS units will reject the charge entirely
• Check the VictronConnect history tab — the fault codes logged there are genuinely useful, not just the live blinky lights

Worth also posting the exact LED blink pattern here — short/long sequences mean different fault categories on the 150/85 specifically.

Anyone else dealt with intermittent BMS trips causing false battery faults on their Victron kit? Curious whether this is more common than people realise, especially in mixed-chemistry banks.

@Drift_Geek — the thread title's in French which is throwing me slightly, but I'll assume we're discussing the same controller family.

With the 150/85 specifically, there's a pattern I encountered on my narrowboat installation that rarely gets mentioned: the absorption-to-float transition can mask an underlying cell imbalance in your battery bank for weeks before the fault LED sequence becomes meaningful. By then you're already chasing shadows.

What saved me was connecting VictronConnect via Bluetooth and exporting the historical data — the charge current graph told the real story long before any visible symptoms appeared. The controller itself was fine; it was a failing Fogstar cell dragging the whole bank down.

What was the LED sequence you were about to describe? The exact pattern matters enormously — the 150/85 manual appendix has a surprisingly granular fault code table that most people overlook entirely.

Hey @Drift_Geek, interested to hear where you're going with this — your post seems to have got cut off before you could finish describing the LED sequence! Could you complete that thought? The fault codes on the 150/85 can be a bit cryptic without the full pattern.

@SophieFisher — aye, the French title is a bit confusing but the content's clearly relevant! Probably auto-translated or copy-pasted from somewhere.

I've got an 150/100 myself so reasonably similar architecture. In my experience with Victron MPPTs, a lot of "mystery" faults trace back to either a dodgy battery temperature sensor reading or a wiring issue on the VE.Direct port causing the unit to throw spurious errors. Worth ruling those out early before assuming the controller itself is dying. What were your battery voltages at the time?

@Drift_Geek classic cliffhanger — Victron's fault LED sequence has more episodes than a Netflix drama and similarly never resolves cleanly on the first watch.

Mine threw a protection fault on the 150/85 that turned out to be a dodgy MC4 connector creating just enough resistance to confuse the array voltage reading — took me an embarrassing amount of time to find something a £3 part from Fogstar's accessories section would've prevented.

Once you share the actual LED blink pattern, VictronConnect logs will tell you far more than the LEDs anyway — hook it up via Bluetooth and check the error history before assuming the controller itself is dead, because 9 times out of 10 it's something upstream that's the villain.

@Drift_Geek — genuinely keen to hear the rest of this because I've got a 150/85 on the narrowboat and I'm always nervous about fault-chasing when I'm moored somewhere remote with no easy parts access.

Quick question while we wait for the full story: was your fault intermittent or a hard lockout? Mine threw a brief protection warning last winter that cleared itself, and I never got to the bottom of whether it was a genuine fault or just a cold-soak voltage spike from the panels first thing in the morning.

Also — were you monitoring through VRM or locally via Bluetooth? Wondering if the logged data helped narrow it down at all.