Mex,
That's why I don't use an ampere hour meter. I use an actual ammeter and voltmeter that I've wired permanently into the RV battery bank circuit. The two meters are mounted on the dash on the driver's side of our small motorhome.
Eventually over time I learned how the AGM batteries react to time, temperature, and charging rate with both the RV converter and engine alternator. The AGM batteries and myself had to become buddies down through the years - it took awhile, though - and the relationship isn't a complicated one. ;)
P.S. Thanks for the clarification, as I always thought that wet batteries required higher charging voltages occasionally to keep their liquid chemistry homogeneous whereas AGM batteries, since their liquid is bonded in a matrix, didn't. I knew that AGM batteries could utilize higher charging voltages for faster charging, but didn't actually need higher voltages for any electro-chemistry reason.