A single 12v, deep cycle battery is of limited use when dry camping, and I suspect you'll find yours is shot.
Look into a pair of 6v golf cart batteries as replacements, you'll be power up for almost twice as long. ( But you'll still have to manage power, by limiting use.
The next variable is the charging from the gen set.
Were you powering the whole RV and charging through the Converter/Charger , or hooked up direct to a 12v output on the gen set?
If powering the whole RV then there are limits ; C/C max output , will slow the recharge.
More info on this web site.
The 12volt Side of Life (Part 1)