Periodically you should check your battery's State of Charge. Being an agm battery it should rest at 12.7 volts pretty esily and if it sags below 12.6 volts you should charge it. This measurement is taken 3 plus hours after the car has been turned off. It is important to check because when a battery discharges it sulfates and when it gets recharged it desulfates, left low for too long the sulfation turns into an insulator to the point you lose part of the battery and an alternator can not deal with it properly. An alternator is a bulk maintainer NOT a full on battery charger, a good intelligent battery charger can charge a battery to a fuller capacity which helps prolong the batteries lifespan.