How long to charge 12v battery with 100 watt solar panel.
How long to charge 12v battery with 100w solar panel.
To get the most effective charging by a solar panel you have to maximize the amount of current by keeping the board pointed directly to the sun.
10 watt 18 volt solar panel charging a 12v 10 amp hour lead acid battery 120 wh from 50 full to full time 60wh x 2 10 watts 12 hours.
Environmental factors will likely increase charge time.
In most cases a solar panel that produces 1 amp of current takes 5 8 hours or more depending on the size of a battery.
The solar charge times above assume a 25 degree celsius day with the panel pointed directly at the sun.
The short answer is in most cases depending on the size of the battery it will take around 5 8 hours to fully charge a 12 volt car battery with a solar panel that can produce 1 amp of current.
Some quick rules for estimation.