Personally, I would rather keep my battery below about 13.8 volts. Anything higher, and it seems to warm the battery case, and I know that can't be good for the battery.
I mainly use my solar system to charge the batteries. When I would use the generator and inverter/charger, it would start out around 45 amps then fairly soon drop to about 35 amps, and I don't think it ran over 14 volts.
When on shore power, if I used the charger, I would set it to about 30% max amps, or about 21 amps, so that it charged at a slow rate, and did not warm the batteries.
I had 4 golf cart batteries.
Fred.