Let's assume your house bank is properly sized for a day's use and therefore uses 1/3 of 1600 AH while you cruise extensively. Consequently, you have to replenish approximately 500 AH every day. Since your battery bank is so large, the acceptance charge rate (40% of battery bank for AGM) is not a limiting factor. You want to be able to limit generator run time to a couple of hours per day and maximize AC generator capacity. A standard approach to achieve this would be to ADD two new 100A three-stage DC chargers to your system and to wire all three chargers in parallel for a combined output of 300A. Each charger will poll the house bank voltage and adjust its amperage output accordingly.