Renewable energy
Outdoor connectors
The two main plugs you want for outdoor DC work are Anderson plugs and standard solar connectors (MC4).
Anderson and MC4
Andersons are brilliant for battery links, pumps and anything you want to unplug quickly. MC4 is what your panels speak. I get both from AliExpress.
Buy yourself a decent crimp tool while you are at it. Crimping is a great skill to learn. Do it once right and your joins stay solid in the rain for years.
For Anderson plugs, this video on Anderson connectors is a great walkthrough.
For MC4, this how to crimp MC4 solar connectors video covers the panel side.