A little update, very belated: I took out the inverter. Took out the fan. Outside of the inverter, when connected to 12v, the fan runs fine. Not quiet, but strong and without undue vibrations.
I have a feeling that this fan operates on demand and at variable speed, and the inverter does not properly control this fan.
Te error it was giving me in freezing weather, was about internal circuits overheating and not about battery overheating.
Given that, I am wondering if I should just give up on this inverter due to its disastrous misbehavior (killing batteries at random) and just purchase a brand new inverter.
If so, which one would you recommend, this one is a 2 kW inverter.
Thanks
