It all depends on storage temp and what kind of trickle charger you have. Freezing conditions are very hard on batteries, especially when they're not being used. It's best to take the battery indoors where it can stay warm if your garage isn't heated. A trickle charger is ok to freshen it up every few weeks while being stored, but if you want to leave it plugged in all the time you need a charger with a maintenance mode that isn't putting a charge on constantly, because the small PWC batteries have a relatively small capacity. I'd worry about overcharging with an unregulated trickle charger.