I have my Nomad stored away in the garage for the winter. I have it hooked up to a battery maintenance charger with a "red" charge light and "green" fully charged light. For the past two months I have turned the charger on for the 1st and 15th of the month. It only stays red for an hour at the most and then turns to green. Am I charging the battery correctly or should I be leaving it connected even though it is indicating fully charged?? Thank you.