hmknightnc wrote:
A theorietical calculation for consideration assumming perfect conditions and battery voltage maintained at 12.5 to keep both controllers in bulk charge mode and that maximum power point for the 100 watt panels is 18volts giving a Imp of 5.5 amps
I was with you up to this point. Help me out with where that MPP voltage comes from?
A 100w panel with a bit lower Vmpp will give more amps than that via PWM, and higher will give fewer, even at Theoretical STC conditions. And both these type of panels exist. I am not aware of any theoretical contrainnts that would drive the max power point to 18 volts.
I would think to get a good theoretical basis for Vmpp you'd pull the Vmpp off the temp curve for the panel based on an IR reading of panel temp, then scale it for the approximate light intensity actually hitting the solar cells from the closest Power vs Voltage curve you can find at a given illumination.
Jim