Using my solar panel over the winter

[steel]

If the panels get covered with snow the fan will slowly drain the batteries down if the solar panels get covered with snow. If the fan uses 0.1A and you have 500AH in batteries total after 2500 hours (3.5 months) your batteries will half way discharged. Will snow stay there for more than a month or two at a time?

If batteries are kept not fully changed they deteriorate. This process happens more quickly at higher temperatures. If allowed to drop too low during the winter they could freeze and be ruined.

You could change the batteries and then hook the fan to the solar panels directly and disconnect the batteries. If there is snow on them then it will be too cold for mold to grow anyway. The self discharge rate and deterioration rate of the batteries should be a lot lower over the winter. But I would still like to to have them float charging.

You could even get a separate solar float charger for the batteries or a solar powered fan.