If the converter/charger is operating properly (and there's no reason to believe it is not) then it will vary the charge level to maintain the battery properly.
It starts with a "bulk charge" (fast charge) and as the battery charge level increases, it changes to a "normal charge" and then finally, when the battery reaches "near max capacity" the converter/charger changes to a "maintenance charge" that is similar to a trickle charger...
The WFCO converter/chargers will not (if operating properly) overcharge your battery bank.
There is a "BOATLOAD" of information for you to research on the WFCO site:
https://wfcoelectronics.com/support/
The "THEORY OF OPERATION" link on that page is an excellent place to start your learning experience.