Here is a snippet from the Web, and maybe not the final declarative method to 'tell', but worth a look at your existing batt label:
Read the battery label. Liquid--or flooded--lead acid batteries will say "lead acid," "wet cell," "flooded lead acid" or "liquid lead acid" on the label. Gel-filled lead acid batteries will say "Gel-Filled" on the label. AGM lead acid batteries will say "AGM" or "Absorbed Glass Mat," "sealed regulated valve," "dry cell," "non-spillable," or "valve regulated" on the label.
Look at the top of the battery. Liquid lead acid batteries have caps or removable tops unless they say "sealed" on the label. Gel-filled and AGM lead acid batteries have flat tops except for the positive and negative terminals.
Read the battery label. Liquid--or flooded--lead acid batteries will say "lead acid," "wet cell," "flooded lead acid" or "liquid lead acid" on the label. Gel-filled lead acid batteries will say "Gel-Filled" on the label. AGM lead acid batteries will say "AGM" or "Absorbed Glass Mat," "sealed regulated valve," "dry cell," "non-spill able," or "valve regulated" on the label.
Look at the top of the battery. Liquid lead acid batteries have caps or removable tops unless they say "sealed" on the label. Gel-filled and AGM lead acid batteries have flat tops except for the positive and negative terminals.
Read more :
How to Tell the Difference in Gel, AGM or Standard Batteries | eHow
I have never had to deduce whether a current batt was wet cell or AGM, as I have always replaced wet cell, or whatever it was, with an AGM, problem free. But all in cars/m'cycles that didn't need 'registering',
GL, mD