Mex, I do not have that kind of charger that can do that! Maybe an alternator with a fancy regulator like they use in big yachts?
Gas is $5 here but I don't really care how much the Honda gen uses to do a 50-90 on my batts in two hours. I think I can do three on a tank costs $12 to fill, so that would be about $4 each roughly. That means if I could cut down to an hour vs two, that would save me $2 a 50-90.
In our case, four days is two 50-90s and we do that say five times Oct-March, then we go on summer routine Apr-Sep when we might use the gen another five times. Varies. Been here a month now with solar and had to use the gen twice the first week, then not since. Anyway, call it fifteen 50-90s a year. That's $60 a year in gas for the Honda.
This is not Mex's situation and does not require spending big bucks as a one-time shot to save gasoline while full-timing where it is hard to get gas.
IAW as always, it is situational what is "worth it" to each individual RVer. What Mex shows is that there are indeed options available not often mentioned in the usual battery blurbs.
