I had to replace the battery in my 23B. It requires a group 27 deep cycle battery. Found out when the dealer replaced the battery a few years ago, they put in a24 cycle. Anyway, It has been about wee...
Since you have power to run a charger, isn't there an onboard charger? I don't know what a 23B is so sorry for the ignorance. A trickle charge could take a couple of days to bring a battery up. You probably basically have a maintainer. Eventually it will catch up.