Bobbo wrote:
When plugging in a portable solar panel, the SOLAR PANEL'S POSITIVE is wired to the covered connector.
This is the practice, yes.
Let's not forget that when you buy a "portable" kit, the connector on the panel doesn't matter because it only goes as far as the controller (that is included in the kit). This controller will have it's own connector on the output that you plug into trailer - could be crocodiles or no connector at all. If there is no pre-existing inline "zamp" controller in the OP rig, he will use the controller that comes with the kit.
110V battery chargers and tenders is an interesting question - but I think they mostly use crocodiles or come with bare wires. Still something to keep in mind.