How much battery power do I need in order to run my lights for 9hrs
I have an 85 Watts solar panel and a 100 watts win turbine that run intermittently and my load is 25 watts Led Light, that runs only 2.08 amp-hrs.
Battery is 12v,120 A-Hrs, 10hrs.
Thanks Gerardo Martinez.
Comments
pcllaredo,
The basic answer is 2.08A x 9 = 18.72 Ah of usable capacity.
I'm guessing that you have a 12v system - so for every 9 hours of reserve capacity, you want 20 Ah of battery time.
So, if you were only going to run the lights for 9 hours, and you knew that you would have plenty of sun to recharge every day - then you'd only need 20Ah of capacity.
Of course, the sun doesn't't always shine every day, so you have to build extra capacity - ie. 40Ah to run for two days without sun.
The great thing about this system is that you have the small turbine. In bad weather, when it isn't sunny it's very likely to be windy and every hour your turbine runs at 100W, it's going to bank about 9A at 12vdc - even at night.
Just start out with the 20Ah of reserve capacity and see how well the turbine fills in. To help ensure that your turbine lasts a long time, make sure that the pole it's mounted to does not move at all in high wind. Use at least four guy wires to stabilize the turbine mast all the way to the top and you'll save lots of bearing wear and tear.