I want to make a water feature using a 1.5A 12v pump that runs off of a 12v battery that is recharged by a solar panel. I am trying to figure out what size of solar panel I will need to recharge the battery each day so the battery doesn't die. The pump would only be ran around 5 hours a day, if that.
The solar panel I found was really small, only $20, and only 2w.
My main question is how long would it take a 2w solar panel to recharge a 12v marine battery to full?
Thanks!
want to make a water feature using a 1.5A 12v pump that runs off of a 12v battery that is recharged by a solar panel.
Power equals volts times amps, so your 1.5A 12V pump needs 18 watts per hour.
The pump would only be ran around 5 hours a day, if that.
OK, so, 90 watts per day, maximum.
The solar panel I found was really small, only $20, and only 2w.
So, in full sun, that panel will require 45 hours to replace what is used in one day.
My main question is how long would it take a 2w solar panel to recharge a 12v marine battery to full?
Unanswerable with more details on the battery, and irrelevant in any case.
You will need more than one of those solar panels to power recharge the battery that powers that pump.
The easy calculation is Pump 18W, solar panel 2 W.
So the pump can be on for 2/18 = 1/9 th of the time.
And that is assuming bright sun no charging losees etc.
So PaulS is right - you need to be looking for a solar panel around 10W at least.
maybe some energy can be regained by a waterwheel?