How much solar watts are required to charge a battery of 35Ah?

To charge a 35Ah battery, the solar panel output depends on several factors, including the battery voltage and charging efficiency. For a 12V battery, the required energy is 35Ah × 12V = 420Wh. Considering an average solar panel efficiency of about 15% and optimal sunlight conditions, you would typically need a solar panel rated around 100-150 watts to fully charge the battery in a day, assuming 4-6 hours of effective sunlight. Keep in mind that factors such as shading, angle, and temperature can affect actual performance.