Here is how I handle my battery charging and why.
I have 4 GC 6 volt batteries on line. They are the cheapies from Sam's Club. 208 amps @ 20 minutes. Thus the four batteries combined are rated @ 416 amps @ 20 minutes. I have a PD9180 w/charge wizard. The Charge wizard is modified so I can turn the voltage up to 15.1 volts or let it run as designed. I also have a IOTA 45 amp converter that comes on line with the 9180 when I run the generator. Thus I can fire up 125 amps of charging when necessary.
I also have 500 watts of solar on the roof.
I spend the winter months off grid, in the desert SW. In the morning I fire the generator for approx. 30 minutes with both converters on line. Once or twice a month I turn the 9180 up to 15.1 volts to stir thing up in the batteries.
After the short generator run time, I let the solar finish up the batteries.
I'm under the opinion, you can hit the batteries with a heavy charge for a short time and not hurt them. Just watch the temperatures and water usage closely. I only have to add a slight amount of water twice a year.
Richard