Solar Wire Size

I have an AC500.
I have 4 x 435w panels: each with Open-Circuit Voltage (Voc) at 85.6V and Rated Current (Impp) at 5.97A. (I bought them used from a solar farm.)
I set up 2 PV arrays (1 for DC1 and 1 for DC2 inputs supported by AC500) and need to run 50ft of wire. Which size of wire should I use? I am thinking of 8awg but looking at Bluetti-provided MC4 seems like they are at 12 or 14awg and the MC4 at the panels is probably 12 or 10awg. Is it because they can be the smaller sizes as those are short? Is there any issue connecting an 8awg to Bluetti 12awg or smaller through MC4? Thanks for your help.

Thanks in advance for your help. See my installation attached.


For the additional 50 feet I can recommend 12 AWG since the current is less than 10 A. In my own installation I used 14 AWG and my longest run is about 30 feet but I see no resistive losses or voltage drops in the wire at that length. The weakest point with the most resistance will be the actual MC4 crimp connections. Build a test wire with the best crimp tool you can buy or use, and measure the full wire resistance between connectors at both ends. It should be extremely low. Then build your longest runs first. The best MC4 connectors should not add any resistance to the wire.

Hi, thanks for the input. In the best condition, I believe those two panels in parallel exceeds 12A. I am using a 12awg to test near the panels with no issue. But for the piece of mind as I run them through our attic… it does not hurt to oversize right?