You need to make sure you have a smart mode converter/charger setup. Your older RV may not have one unless it has been updated.
Using smart mode charging will re-charge your batteries to their 90% charge state in a quick three hour generator run time...
If your converter/charger only puts out 13.6VDC when being run by the generator it will take a good 12 hours to get your batteries up to their 90% charge state,
A smart mode converter/charger will hit your batteries with 14.4VDC for two hours and then drop back to 13.6VDC for another hour.
Roy Ken
