It's just a battery tender/charger guys.....no need to complicate things.

SD, you learned the hard way. I lost 2 ~high end~ AGM's last year while troubleshooting electrical issues. We're talking about $900 in lead lost..

Anyhow, agm's are more ~sensative~ when it comes to batteries. Wet Cells can take a higher voltage, burp and be fine. FWIW, SOME AGM's like to even be charged at high amp rates like 40-50 amps when deeply discharged.

There is no universal rule when it comes to batteries. However, the one rule I would follow is keep it at 14.7 MAX on AGM on the charge profile for AGM's and you can use higher maintenance voltages on wet cell, but IMO do it ONLY if you think you need to. 1st order would be to just give it a full charge on your charger, see if she holds and then IF you believe you may need to add a battery desulphate into the process, then do the recondition.