[jxnbbl]

Interesting enough I started at 400w and changed out to 2 100ah AGM batteries from the beginning since i wanted to ensure the 12V fridge and the heat would work "without question". I have not been disappointed. I now have 3 170W panels, 2000W inverter with the original batteries. At the current time I basically only turn on the inverter for coffee, TV, power tools and sometimes external lights.



I've entered a number of posts in here on the installation of this system and my mistake of putting in a 2000W inverter/charger. Naively I didn't realize that the charger portion can not be turned off...I've fixed this but that is off track from the OP. The part that is relevant is running a 1000W inverter with the fan for a meaningful period of time is probably a lot bigger draw than you think. You probably want to look at the stored data on your controller for "the end of the day" when you stop using the fan.



Personally I would change all of this at your house incrementally. (if you can park there).



1. (as others have stated)....increase the battery resources as the first step and figure out other non-inverter fan solutions. - money well spent anyways.



2. Monitor the charge rate after a night of running the furnace and the fridge only. (when does the controller indicate a full charge?).


3. If #2 doesn't happen after long hours and a "cloudy day", then look at adding another panel or supplement it with a portable panel as you probably have another solar port for that purpose.



If you upgrade the roof panel you will probably have to upgrade to a 20A (I'd go to 30A) controller.