How do I know which setting to use on my battery charger?

I can't tell if my lawn tractor battery is wet, gel or AGM, and a new charger requires that I push a button to make a choice. The old battery (in need of a charge) has two long plastic pieces on top that are similar to the old-style cell caps, but I don't think they're supposed to come off. The new one has nothing like that on top. Neither battery indicates which type it is. How do I safely set the charger for these batteries?How do I know which setting to use on my battery charger?Look on the battery for a telephone number or a marker for type or stock number. Find a number to a local tractor place or the 800 number for your tractor company and ask them. They will point you in the right direction. If you do not see any type of cap for water to go into.....It is probably a gel type. They usually have a greenish top. ;)How do I know which setting to use on my battery charger?old battery sounds like a wet battery.....should say on label on the batteries what type they are.......