Solar
OK, I am ready to install my system which will be 2 255W panels, 45a MPPT controller, I have 2 12v 80 ah batteries which are new and will be replaced in the future with AGM's. The only thing I haven't...
Forum Discussion
JiminDenver wrote:
No games, just options and their consequences.
My decision was't because of what happens when one of the panels are shaded, we don't get a lot of shade up there. It was because I would lose up to 10 amps at peak in series and have a hot running controller for it.
As for shading and shadows, the test I ran last year showed that in series a weaker or weakened panel will weaken the whole string and confuse the controller. Other panels may differ.
Now I have three panels that at altitude will have more than 30 amps coming down in parallel. That's more than MC4 10 gauge gear can handle so I have 1/0 welding wire for the job. Over kill yes but it was cheaper than a thinner gauge new. With two panels you really wouldn't have to spend much more for the difference in wire needed for parallel vs series.
I'm hoping to reseal our roof before the install, that is if we don't get a foot of snow this weekend.
I don't think we'll get snow but it is Colo. Jim one concern as you stated is heat and if I go with parallel I surely would need to run larger wire down from the j box correct? Series is easier I believe but what is more efficient? I have solar on the house and if one is shaded then the whole system has a lower output but one a RV its charging batteries
