Recharge time is all about the charging rate and having enough generator VA to run the charger(s) You can do a 50-90 in two hours with a 30% charging rate (any size battery bank), which is the max rate usually given for deep cycle Wets.
I can recharge my 700AH bank 50-90 in more like 2.5hrs with 140 amps (20% charging rate) going in but I can't recharge faster because the Honda 3000 can't handle more chargers of the kind I have.
You would need to calculate your AH usage for the heater or air conditioner, then know how much gen time you would have, then fit that AH usage with all other usages into your 40% of AH capacity (50-90) Then you know what the 100% capacity is and now you know how many amps charger you need to get a 30% charging rate to get it done in two hours or what rate you need for the allowed time if time is longer than two hours.
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