I use these on two of my 500 X panels on the 3600+: https://www.amazon.com/dp/B0G2Y7YXQ6 Note that they are depicted here with correct polarity – tongue up, red on the left – but when I bought mine a few months ago, they arrived with polarity reversed on both ends, so I had to slide the connector out of the shroud and transpose them. That is easy enough, though. (Technically, since they are wrong on both ends, that cancels out, and they would work fine, but I didn't want to use them that way because it makes me twitchy.) They're 10 gauge, so the power loss to voltage drop isn't terrible, and this allows a lot of flexibility for panel placement. They're not waterproof, of course, but it really isn't an issue at all since these panels run below 60 volts. I've had zero issues. For my other two 500 X, I bought marine cable, connectors, and a crimp tool, and made my own custom length extension cables, and those aren't waterproof, either, because I don't think it's important for this application. With this setup, the original cable goes to the Jackery and these go between the original cable and the panel.
