PT--"I get 16.9 amps from 256 watts of solar in a fixed flat installation. That works out to 230 watts, so my total losses are lower than 11%.
So your battery voltage is 230/16.9 = 13.6v. OK.
Meanwhile a PWM at 13.6 with 12v panels is not down from Isc hardly at all by IV curve, so using the standard :) method-- 256/130 x 8.2 = 16.15 amps.
That is with panels aimed. but yours are flat. Diff between flat and tilted and aimed varies by latitude and time of year. Let's give you only 10% loss for being flat-- that means your equivalent amps to 16.9 is 110/100 x 16.9 = 18.6 so your MPPT with amorphous panels vs poly also, is 18.59/16.15 = 15%--looks good! (at 13.6 battery)
