Estimating Solar Charge Time for Batteries | Voltaic Systems
Example: 10 Watt, 18 Volt Solar Panel charging a 12V, 10 Amp hour Lead Acid Battery (120Wh) from 50% full to Full – Time = 60Wh x 2 / 10 Watts = 12 hours. Environmental Factors Will Likely Increase Charge Time. The solar charge times above assume a 25 degree Celsius day with the panel pointed directly at the sun. Some quick rules for estimation: