I agree with the others. I have learned that lesson the
expensive way by not doing it when I should have.
Until these battery " minders " came on the market, there was no easy way to simply connect something to your battery and then " forget " about it until the next spring. If an old fashioned battery charger was used all winter, it would always manage to " boil off " all of the electrolyte. If you did nothing, it would build up " bridges " in the cells that would short the plates together. Now with these new battery minders, neither one of these things happen. This is one of the best money saving items to come along in years, IMO.