I was taught how the constant solar charge is not enough amps. The flooded batteries like that big beefy charge. Also the solar controller might not reach high enough voltage. I always forget. Dont we want 14.7 or 14.8? Your controller might allow you to choose a flooded option.
How is the charger on the trailer? You could always cycle the batteries if/when you cycle your generator. Use the trailer charger to pump into the batteries assuming the solar isnt very strong.
I go one step further and store my batteries in the garage. Charge them with my stand alone charger that is fancy and allows for exact voltage and amps. I go months without checking them. They are a year old and only have 20 or 30 cycles on them. Need to get out camping more!!