Originally Posted by BradS7535
1) Is there any advantage to running an MPPT on a single panel?
2) Do I want to look at Vmp or Voc for the MPPT operating (turn on) voltage? I don't want to have to wait for panel voltage to get high enough to turn on the controller.
3) Is there anything else to consider for the Zamp panels for Parallel vs Series? I know series is higher voltage, so less voltage drop in the lines, but parallel is better for shading.
4) Are these panels similar enough to warrant running through a single MPPT? Series/Parallel?
1. Yes. On the panels you describe that have strings of 36 solar cells in series, a MPPT will improve performance between 25 and 30 % vs a PWM charge controller. The percentage improvement goes down slightly if you use series connected panels where there is a larger DC to DC conversion taking place in the controller.
2 and 4. Yes, if you want to wire multiple panels in parallel to a single MPPT charge controller, you can do this, as long as all are the same type of solar cell (mono or poly crystalline), and all have 36 solar cell in series architecture. If so, they will all have very close Vmp values.
3. Output of each group of solar cells wired in series will drop if any one of the series connected solar cells of a panel is shaded. Parallel will minimize losses caused by anything partial shading panels, which can be a problem on a RV roof with things like the TV antenna, AC shroud, even vent pipes and vent covers. Whatever you can do to position the panels and/or park the unit to minimize shading is critical to maximum power production.