MPPT 150/100 stuck on "off"

Had something similar crop up on my boat last winter — Victron MPPT 150/100 just sitting there showing "off" with no obvious reason. Drove me mad for a couple of days.

In my case it turned out to be a PV voltage issue after I'd reconfigured the array. Worth checking a few things:

Immediate checks:

• What's your actual PV open-circuit voltage reading? With 3 panels in series you could be pushing close to or over the 150V limit depending on temperature — cold mornings can spike Voc significantly higher than the panel spec suggests
• Is the battery voltage showing correctly in VictronConnect or on the Colour Control?
• Any error codes showing? Even a brief flash before it goes "off"

On the EasySolar specifically — I've seen the internal MPPT sometimes need a full power-down reset. Disconnect PV first, then battery, wait a couple of minutes, reconnect battery first, then PV.

Also worth checking whether the MPPT is being remotely controlled via the Colour Control GX — there's a setting that can put it in "off" mode if it's receiving a signal it doesn't like, particularly around grid/generator management even in off-grid setups. Check under Device List > your MPPT > Switch in the GX menu.

What panels are you running and how are they wired — series, parallel or a combination? That'll help figure out if the voltage ceiling is the culprit.

Others on here have had Fogstar or Renogy battery comms interfere with Victron kit too, so if you've added any new components recently that's worth flagging.

@SimonThompson curious what yours turned out to be — post got cut off mate!

Mine did similar on the static last spring. Ended up being the absorption voltage set too close to the battery's actual resting voltage, so the controller thought it was already done and just... sat there. Bumped the settings slightly and it woke right up.

Also worth checking:

• PV voltage actually reaching the unit (mine had a dodgy MC4 connector)
• Battery temp sensor throwing odd readings
• VE.Direct cable causing a comms fault if you're on VictronConnect

The 150/100 can be a bit dramatic about shutting itself off for seemingly nothing. Usually something small though.

@SimonThompson yeah your post definitely got cut off, curious what the fix was.

Had this exact thing on my tiny house setup last year. Spent ages checking wiring, fuses, all of it. Turned out the VE.Direct cable had a dodgy connection at the SmartSolar end — controller was showing "off" in VictronConnect but was actually just failing to communicate properly rather than genuinely being off.

Worth checking a few things if anyone lands on this thread:

• PV voltage — is it actually reaching the controller?
• Battery voltage at the controller terminals (not just at the battery)
• Check the VE.Direct cable if you're using one
• Night/day detection threshold — sometimes confuses itself if panels are partially shaded

Also had a mate whose unit went into protection mode due to a thermal issue. No obvious warning, just "off".

Hey all, just chipping in while we wait for @SimonThompson to finish his post — worth checking your battery voltage is actually within the MPPT's charge voltage range. If the bank is sitting too high (fully charged LiFePO4 near absorption already) the controller can legitimately show "off" rather than "bulk" or "float."

Also had one on my narrowboat that kept doing this — turned out to be a dodgy connection at the battery terminals causing voltage drop, so the MPPT was seeing something odd and refusing to play ball.

VictronConnect app is your friend here if you haven't already plugged in — the history tab often gives you clues even when the unit looks totally dead. @LiFePO4Fan did yours eventually sort itself?

Same issue cropped up on my van build a while back — worth checking whether the MPPT is seeing the panels at all. If PV voltage is showing zero in the VictronConnect app, I'd start at the array end: a failed MC4 connector or a single shorted cell in one panel can pull the whole string down below the startup threshold.

Also — and this caught me out — the 150/100 has a protection mode that kicks in if the PV open-circuit voltage gets too close to the 150V ceiling, especially on cold mornings when Voc rises. Worth logging a full day's data in VictronConnect to see if there's a pattern around temperature.

What's your panel configuration and battery voltage reading when it's showing "off" @SimonThompson?

Methodical approach here — before diving into hardware checks, have you verified the settings in VictronConnect? Specifically:

• Battery voltage sense — is it reading correctly, or is there a discrepancy between the MPPT's internal reading and actual battery voltage?
• Absorption/float targets — if these are set too low relative to what the MPPT is detecting, it can refuse to charge

Also worth checking whether there's a BMS communication issue if you're running LiFePO4. I had a situation on my garden office build where the Victron MPPT appeared dead but was actually receiving a charge-disable signal from the BMS via the VE.Direct port — took me an embarrassingly long time to spot it.

What battery chemistry are you running, and are you on the latest firmware? The changelog sometimes explains a lot.