Have a 5th wheel and just went out to load for trip over New years and slides won't go out. Think battery is dead, and it's a new battery. Should I leave plugged in to electricity while in storage? It's only been about a month since we used it last. Does the winter months take more of a toll on batteries than spring and summer months? Will being plugged into electricity now charge up the battery, or do I need to put on a charger? I'm new to all this.