Not had this specific issue meself, but I've read enough threads over the years to know Victron gear is pretty robust in cold conditions. That said, there's definitely some nuance to how lithium and MPPT controllers behave below freezing.
What's your setup like? Are you running lithium or lead acid? The reason I ask is that most MPPT issues in winter seem to stem from the battery side rather than the controller itself — if your battery management system cuts charging when temps drop, the MPPT will just sit there with nothing to charge into.
I've got a Victron 150/35 on my narrowboat, and it still performs well through winter, but I've made sure my LiFePO4 pack has a decent heater. The MPPT itself handles the cold fine — it's more about the whole system talking to each other properly.
Worth checking:
- Your battery's low-temperature cutoff settings
- Whether the MPPT is actually getting good solar input (panels covered in frost/snow?)
- Cable connections haven't loosened up with thermal cycling
- Your firmware is current
Have you tried a full system restart? Sometimes these things just need a power cycle. Also, if you've got VRM access, check what the MPPT is logging — that'll tell you if it's actually seeing panel voltage or if the issue is downstream.
Keen to hear what you find. Cold weather definitely brings out the gremlins in off-grid setups, but Victron stuff usually comes out the other side alright.