PWM or MPPT.

[GQtdauto]

Correct me if I'm wrong @Cuppa but basically the PWM charges are in short regulating on off switches.
They switch on at a set voltage and off at a set voltage.
Not sure if top end PWM chargers can supply a float voltage but my cheaper one doesn't. .

As for pannels, try find them without controllers.

They are usually cheaper..

Pretty much spot on , yes the better quality PWM do have a float , one of mine does the other gives so much at 14.6 or whatever it can then after a predetermined amount of time switches to 13.1-13.3 but even the cheap one is adjustable , if only I could read Chinese Engrish.