Can I Add a 400W Solar Panel to My Existing System?
Asked by SunnySkyChaser
I'm currently using a 6-input combiner with six 100W solar panels connected to a Vectron 100V/50A charge controller. This setup supports decorative lights, outdoor surveillance cameras, and my garden tools' battery chargers. I recently installed an attic fan that pulls about 350 watts, and I want to add a 400W panel to this system to power it. The problem is, when I try to run the fan, there's no power left to charge my two 200Ah FeLION batteries. My main concern is that the 400W panel will produce more than 10A, and since I can't add it to the existing combiner, can I connect this new panel directly in parallel with the combiner's output into the charge controller?
Answers
It sounds like you might run into voltage issues since a 400W panel could indeed produce higher voltage, nearly doubling that of your 100W panels. Instead of just connecting it directly, I'd suggest reconfiguring your 100W panels to a 2s3p setup. That way, you can link the 400W panel in parallel with that configuration for better efficiency.
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GreenThumbGabe: Thanks for the suggestions! I'm considering getting four more 100W panels to try the 2s5p setup that you mentioned. Plus, I've got a second MPPT controller and some lead-acid batteries, so I might make an entirely separate system for the fan since it won't run overnight.