If you are keeping the boat out of the water during the freezing months as I do, I pull the batteries all together and keep them warm in my garage and can top them off several times in the winter. Precludes any electronic gremlins happening while the boat is under covered storage on the trailer. If you are keeping your boat in the water, then, of course, you would want full time bilge function. I use to resist pulling the batteries, but over the years, my batteries last longer and it is also a chance to clean up the battery compartments year to year.