boondocking with just a generator to recharge the batteries

Running the generator will keep you functional but to really top off a battery always requires that slow long term charge. If you are willing to run the genny just add a small solar panel, 100 watts and let that finish the battery for you.
Also the battery does sound questionable. You may want to change to a larger battery, there are some AGM batteries at Helmart now with a single batter offering 150 or so amphrs in a package similar size wise to a group 27 deep cycle for less than $300.