The "yes" answer would mostly be right but why not do it right? I've found that putting more than a few amps through a cigarette lighter plug
can result in a melted plug (don't ask...).
For solar panels
I like to use a new, separate circuit for each battery bank.
Others would have more knowledge and/or/experience than me but my understanding is that you need a double bus bar (or two singles) with a substantial fuse between the positive bar and the battery.
Get a reliable controller, wire the panel(s) to the controller and then to the bus bars.
Use good thick properly sized tinned wire and good quality crimp terminals.
There's probably a standard that sets things like wire colour etc.
A bit of research