1 March 2024 Update: I have been monitoring this system since I set it up and it looks like I typically use 12% of the battery capacity over the 14-15 hours that there is no sun. Because of the mountain to my south, no direct sun hits the solar panels until about 9:00 in the morning. This early in the year, sunset is at 5:00. That gives me eight hours of sunlight, though there is some reflected light before and after those hours. Even so, the Delta Pro is fully charged by 12:00 noon and stays fully charged until the sun goes down. My peak collection time, because of the orientation of the panels, is between 12:00 and 2:00. During that time, I am inputting between 850 and 1,200 watts of electricity.