What is your alternator size? That would be my first question.

The bank won't get the 40 amps very long -- and it won't see continuous charging of much more than 30 amps. (The charger's have internal heat that causes them effective to "de-rate" themselves as the back-off. Then, it will eventually "back-off" as the voltage comes up.

If you are replacing the charger or inverter charger: i) make sure the charger is in a cool, ventilated place; ii) I would go with one that has a rated capacity of more than 15% of your AH capacity.