Yeah, had this nightmare on my narrowboat last winter. Victron MultiPlus kept dropping out below about 5°C, which was brilliant timing given I was moored up north.
Turns out it wasn't actually the charger itself — it was the battery doing the classic "nope, not accepting charge when cold" move. LiFePO4 has low-temp cutoffs for a reason (damages the cells), but my old AGM was just being stubborn. Once I wrapped the battery bank properly and added some basic insulation around it, sorted.
That said, Victron does have some thermal thresholds in the firmware that'll throttle things if it detects a dodgy temperature. Worth checking your settings in VEConfigure — might be overly cautious depending on your setup.
What I'd check:
- Battery temperature (not just ambient)
- Your actual charger firmware version
- Whether it's cutting out completely or just reducing charge current
Also depends whether you're running lithium with BMS comms or traditional chemistry. Makes a difference.
Anyone else dealing with this? Curious if it's a widespread issue or just us unlucky sods in less insulated setups. And more importantly — what's your battery type? That's usually where the real answer lives.