MPPT100/50 auf einmal "aus"mit #OR4: per Fernzugriff oder BMS deaktiviert

So this one's been keeping me up at night, and I figured if anyone's seen it, it'll be someone here.

Running a Victron SmartSolar MPPT 100/50 on the shepherd's hut — been solid as a rock for two seasons. Then three days ago it simply stopped. Not tripped, not alarmed, just off. The status in VictronConnect is showing #OR4: disabled by remote or BMS, which from what I can gather means something upstream has told it to stand down.

Here's where it gets murky for me. My setup is:

• 2× 200W Renogy panels
• Fogstar 100Ah LiFePO4 with its own BMS
• No Cerbo GX, no VRM, no remote switch wired in

So nothing should be sending a disable signal. I haven't changed anything in the app, no firmware updates, nothing. The battery BMS has a charge-inhibit line but I didn't think I'd connected it to the MPPT — though I'll admit the wiring inside the hut has grown a bit organic over time, if you know what I mean.

Has anyone seen a Fogstar BMS spontaneously assert charge inhibit and effectively ghost the controller like this? Or could there be a setting buried in VictronConnect that's latched itself somehow?

I did briefly consider the narrowboat setup might offer clues — similar Victron gear there — but that one's running a Cerbo so the comms picture is completely different.

Would really appreciate if anyone's untangled this before I start pulling terminals in a field.

Hey @HazelDawn, that thread title gives it away a bit — #OR4 is the Victron error/status code meaning the charger's been switched off remotely, either via VRM, a connected BMS, or something on the VE.Direct/VE.Smart network asserting a charge disconnect signal.

First thing I'd check is whether you've got a BMS in the loop — even indirectly through a battery monitor or Venus device. They can send a "stop charging" command and the MPPT obeys without complaining loudly about it.

Also worth checking your VRM dashboard to see if there's a scheduled charge profile or an automation that's kicking in unexpectedly.

If you're not running any of that kit, check the VE.Direct cable — a dodgy connection can occasionally cause phantom signals. What else have you got connected to the MPPT?

@CraftyWelder's got the OR4 bit covered, but worth checking your VE.Smart network — if you've got a BMV or SmartShunt gossiping with the MPPT via Bluetooth, a dodgy BMS signal can make the charger go full drama queen and shut itself off "for safety."

Happened to me in the shepherd's hut last January; turned out my Fogstar battery BMS was throwing a strop over a cold-soak voltage sag and basically telling the MPPT to do one.

Check VictronConnect > MPPT > History > Error log and also peek at whether DVCC is enabled on a GX device — that hands charge control over to the BMS entirely, which is either brilliant or a nightmare depending on your wiring.

@HazelDawn one thing worth checking that nobody's mentioned yet — if you've got a Cerbo GX or even just the VictronConnect app still open on a phone somewhere, there's a known quirk where a dropped Bluetooth connection mid-session can leave the charger in a remote-command limbo state.

Also, check your BMS charge enable signal if you're running lithium — Fogstar Drift cells for instance will pull that line low on a high-voltage event and the MPPT obeys instantly. It won't necessarily throw a fault you'd notice; the OR4 is the only indication.

Worth pulling the history log in VictronConnect and cross-referencing the exact timestamp of the OR4 against any BMS log you have. That'll tell you definitively whether it's a network command or a BMS-driven shutdown rather than guessing.

@CrispyMender raises a fair point about the Cerbo, but also check your BMS if you've got one — a lot of people wire their BMS charge-enable signal into the MPPT's remote on/off port and then forget they did it. First cold snap or high-temperature event and the BMS pulls the pin low, MPPT shuts off, looks like a mystery.

Had exactly this on my garden office setup with a Fogstar Drift 200Ah and a Victron SmartSolar. Took me an embarrassingly long time to work out the BMS was doing its job correctly — I just hadn't realised I'd connected it that way months prior.

Check the remote L/H terminals on the MPPT and trace the wiring before assuming it's a software or network issue.