How long can a battery possibly last

My old cars and truck that I drive once a week or so I use to put on a trickle charger. I ordered a new original MOPAR looking battery for my car recently. The sales person said to charge it with a 10 amp charger every other month and skip the trickle charger. FYI...
I went out and it took three to four hours with each battery, on a charger, to get a full charge. Might be some truth to that??