So I bought a 45W photovoltaic kit from Harbor Freight which comes with its own charge controller ($139 on sale), a used deep cycle battery with 135 amp-hours, and a 1.6 amp DC pump that moves over 300 gallons per hour. Yeah I know I should have done my calculations ahead of time but here they are, after the fact. 1.6 amp X 12V comes out to 20W per hour times 24 hours for (roughly) 480 watt-hours…