MPPT 250/70 Solar lädt nicht mehr

Had something similar crop up with my Victron SmartSolar 150/70 last autumn — woke up one morning to find it had just... stopped charging overnight. PV voltage was showing fine in VictronConnect, batteries were reading low, but the controller was just sat there doing nothing.

Turned out in my case it was a combination of a dodgy BMS communication dropout and the MPPT going into a protection state it wasn't recovering from automatically. A full power cycle sorted it, but it took me a while to figure that out.

For anyone running an EasySolar 2 or similar integrated unit with external control (DVCC via Cerbo GX, presumably?), I'd check a few things first:

• VictronConnect history — any error codes logged around the time it stopped?
• DVCC settings — if an external BMS or Venus OS is issuing charge current limits, it can sometimes push the limit to 0A without being obvious
• PV input voltage — 190V is fine, but check the actual wattage being offered vs what the controller is accepting
• Firmware — Victron pushed a few updates last year that fixed some edge-case MPPT behaviour

The integrated nature of the EasySolar makes fault-finding a bit more layered than a standalone MPPT, which is why I ended up going with separate components for my garden office setup. More flexibility when something goes wrong.

Anyone else had their MPPT lock up unexpectedly? Curious whether this is more common with externally controlled setups vs standalone.

@DustyNomad — worth checking whether the unit had dropped into absorption float cycling and then triggered an over-temperature shutdown overnight. Victron's thermal protection is quite aggressive, and if your controller is in a confined space (mine was tucked behind a bulkhead), ambient heat from daytime can linger and cause false trips even when air temps drop.

Pull the full history data from VictronConnect — specifically the "Last Error" field. If it shows #17 (temperature too high) or #21 (input/battery voltage mismatch), that narrows it considerably.

Also check your battery sense wiring if you're running remote sensing — a loose connection there can cause the MPPT to effectively "see" a full battery and halt charging mid-cycle. Happened to me with a Fogstar Drift 200Ah over winter.

Has anyone checked whether the battery temperature sensor is feeding incorrect readings into the charge algorithm? I had a weird one with my SmartSolar where the unit was convinced the batteries were warmer than they actually were, which caused it to throttle right back — looked like a charging fault but was actually over-temperature compensation kicking in incorrectly.

Worth pulling the raw data logs from VictronConnect — does the charge current actually drop to zero, or is it just showing a very low figure? Also curious whether this is a lithium or lead-acid setup, because the charge profiles behave quite differently when something upstream goes odd.

@DustyNomad I had a very similar head-scratcher with my 100/50 last winter. One thing nobody's mentioned yet — have you checked your battery voltage sense wiring? If the remote sense leads develop a poor connection, the controller can "see" a falsely elevated battery voltage and decide it's already full, so it just sits there doing nothing despite plenty of PV available. Caught me out for two days before I spotted it. Also worth pulling the history data in VictronConnect — look at the "maximum battery voltage" figure for that day. If it's reading suspiciously high, that's your culprit right there. Dead easy fix once you've identified it.

@DustyNomad had almost the exact same thing with my SmartSolar 100/30 on the cabin last February. Turned out to be the VE.Direct connection had worked itself slightly loose — controller looked fine in the app but wasn't actually syncing properly with the battery state.

Worth also checking your absorption voltage setting against your actual battery spec. Mine had drifted somehow (still not sure how) and was cutting out early thinking it had finished.

If you're running Fogstar or similar lithium, double-check the BMS hasn't quietly tripped and reset — that can look identical to a controller fault from the outside.

@DustyNomad one thing worth checking that nobody's covered yet — absorption voltage cutoff. If your battery voltage happened to be sitting just above the absorption threshold when the MPPT polled it (can happen with residual surface charge after a partial load disconnect), the controller assumes charging is complete and parks itself in float or switches to a long tail-end absorption timer that looks like it's done nothing overnight.

Pull the full history log from VictronConnect and check the timestamps against your battery voltage curve. If you see voltage spike briefly to absorption setpoint right before it stopped, that's your culprit.

Happened to me on my T6 setup with a Fogstar 200Ah LiFePO4 — ended up trimming the absorption voltage down 0.1V and it never repeated.