I currently have 2 x 100 watt solar panels on the roof of my caravan in parallel and going to a Victron MPPT 75/15 controller. Can I add another 100 watt panel to the roof in parallel? I have an A/C unit between the two existing panels, so shading could be an issue. I know that 15 amps is the max I will get out. Just don’t want to blow anything up!
Thanks
Hi @Big Ste. If your 100W panels are rated for 12V (typically an open circuit voltage in the region of 17 - 21V) then it means it can deliver roughly 5A each, or maybe a tad over 5A. The maximum input current on the 75/15 is 15A, therefore the third panel connected in parallel might, in the right conditions exceed the input limit and actually damage it. Maybe it’s time to consider a bigger MPPT?
I am quite sure there is no damage to the MPPT. Overvoltage will break the controller, but with current it just limits itself.
I have a full size solar panel on my 75/15 and in full sun (in Spain) around noon, the current hits 15A and the surplus current/power from the panel is just cut off by the controller.
I don't think there will be a problem, also because the maximum current of the panels it not much higher than the 15A max. current of the controller.
Thanks, that was what I was hoping for, also the panels are flat on the roof so will never give the perfect performance.
I take it to stay with the panels in parallel as well?
Cheers
