Note that these figures show average output.
100w solar panel charge time.
Some quick rules for estimation.
A 100 watt solar panel will charge a 12v battery in around 14 hours under ideal conditions.
I built a solar power system in my back yard and take ap physics at my high school.
Solar insolation in the southern us states is 6 hours of usable sunshine per day it s 4 hours in the northern states and 2 hours in alaska therefore it would take a 80 watt solar panel to recharge that 20 of your lead acid 100 ah battery in a daily cycle for only 240 wh of diurnal draw.
So if you have a solar panel that with a 10 watts power rating and it is exposed to sunlight for at least 6 hours.
How long to charge 12v battery with 100 watt solar panel.
Average watt hours wh produced by a 100 watt panel per day in each state.
Top user satisfied brand for 100 watt solar panel to 12v.
However most people are not dealing with ideal sunlight conditions so it could be much longer.
The flow of electricity is far more efficient when the device is cool however the panel requires direct sunlight and will as a matter of course heat up.
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.
Likewise if i took that same solar panel in miami fl installed it at a 25 degree tilt i d have an annual average of 5 2 sun hours.
This map shows watt hours per 100 watts of solar panel system capacity.
A good quality 100w solar panel may produce 95w a 200w panel may produce 190w and a 300w panel may produce 290w.
So i can look at the charts to see if i have a 100w solar panel in portland me installed at about 45 degrees angle on annual average i d get 4 6 sun hours a day.
Environmental factors will likely increase charge time.
If the battery holds 125 amp hours at 12v then the 100w panel would take about 17 1 2 hours to charge.
You can get the amount of energy it will provide the battery by multiplying 10 watts by 6 hours which will give you 60 wh.
This means that on that scenario the solar panel delivered 60 watts of power to charge the battery.