Let it charge until it says it is done, then unhook it, turn the lights on for a minute or two, and then hook it back up and it will probably charge for a good bit longer. A lot of automatic chargers kick off too early if they are doing more than just maintaining a battery. I don't like automatic chargers but they are pretty much a necessary deal with AGM stuff.

Noco makes good stuff but my favorite charger for at home AGM stuff is the Optima brand ones, I have the 4 amp unit and it has served my 9 year old yellow top well.