Re: AGM Battery Upgrade and Charger
I'm still learning, too :-)
Reaching a full charge monthly would probably be OK, particularly as we're coming on to winter and cool temperatures.
In hot temperatures, it would be better to do it more frequently.
AGMs have a low self-discharge rate (I think Mastervolt claims about 3% per month) so can be left without charging current far longer than flooded batteries, but they DO need to be fully charged at reasonably short intervals.
In really cold weather they will self-discharge much less than in hot weather.