Hi, I am designing a solar system for a RV. My intention is to have Two parallel strings of 600 watts each (2X300 Watts panel in series) for a total of 1200 watts in a 12V LIFEPO battery system which I know will require two parallel charge controllers.

Right now, I want to start with one string of 600; 2X300 watts in series to a Victron MPPT controller.

The second stage of the project will be an identical second string to a second controller making it a total of 1200 watts in two parallel strings. (two identical 600 watt strings to two charge controllers).

I have a couple questions:

1. Which controller would be practical for this application?

2. I am also considering adding a third panel to each parallel string, in the future, bringing the total of each string to 900 watts. Is there a charge controller that will handle these parameters of expanding the 600 Watt string to 900?

3. ALSO considering making this a 24V system. Is it possible to select a charge controller that will be flexible to handle any of these parameters? IE, 600-900 watts, 12 or 24V?

4. Is what I'm intending possible?

300-->300-->(+300 future)--->MPPT1------12 or 24V combined\

300-->300-->(+300 future)--->MPPT2------12 or 24V combined /

Thank you,

Chris A