Re: How long to charge a battery?
A 60 watt panel should be rated at about 17 volts Pmax and 3.5 amps Imax, check the back of your panels for exact values. 12 panels *3.5 amps = 42 amps. You will probably on average on see about 80 % of the rated power depending on your setup. .80 X 42amps = 33 amps. A battery requires about 120% of the power used to replace it. So if my calculations are correct 150 * 1.20 = 180 amp hours to charge the battery. 180 amp hours /33 amps = approximately 5 1/2 hours charge time. In reality you also need to extend that time for absorb time to approximately 8 hours.
I have 12 60W panels in parallel. They have a total current of 10.8A for the panels (.9A each). 300Ah 12V battery bank. If i discharge the bank to 50% capacity (150Ah), what other information do I need to figure out how long it would take to fully recharge this bank? I see the specs of the bank have a reserve capacity of 140min 25A, whatever that is. I have a FM-80 MPPT charge controller. Can anyone help?
IHTH Every body check my math, this is how I learn :)
Last edited by BB.; February 12th, 2010 at 9:15 PST.
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