How much could he fix you up for? LOL He knows you are loaded. Many industrial or cart chargers need to see a MINIMUM voltage to be able to turn on but dont care what they are pumping the juice to. If the charger was set up to charge wet cells it may be too high of a finish voltage for agm. Depends on what the manufacturer of your agm say. Plug it in and monitor the voltage.
I have a 48 v Lester industrial charger on four 12 v series dual purpose Samuals batteries. They hit 61 volts every charge. ages: 2008, 2009, 2015, 2016.
I wouldn't be surprised to see it hit 45 v.
How old is your Lester? Model number?