Question for all you solar experts
I have ordered a 250 watt Sharp 24 volt Solar panel. Now for my question. I would like to use a Morningstar Sun Saver 15 MPPT controller. The problem is that the sales person said that the 15 amp MP...
Forum Discussion
brulaz wrote:
The Rogue manual suggests a little formula for determining the "maximum usable PV array power when taking into consideration system losses"
PV(watts) = (A x Vb) / 0.90
A is the amperage rating of the MPPT controller, Vb is battery voltage, which he takes to be 14.4V for the 3048 with 12V batteries, and 0.90 is the assumed efficiency.
So the new Rogue 20A MPPT controller should handle a 320W array.
By the way, the downloadable manual is a very useful source of info.
Based on the above numbers the sunsaver 15A MPPT controller would be good to about 200W. Based on what I see from mine with a 160W panel, that's formula works out pretty well. With my 160W panel into a bank at 50%SOC I've seen 11+amps into the battery bank with "perfect" sun conditions. Extrapolating to 200W would yield just at 15A, right at the sunsaver current limit.
And I agree, what is needed is a 20-25A MPPT controller. It's big jump in price from the 15Aish to 45A units.
