Iam going on 6yrs with me DC Battery in my Ranger Bass Boat.Ive always charged with a auto charger.
My new charger has a DC setting.

Now on the other hand I only get 2 maybe 3 yrs out of my starting battery..
I also was the battery Tech for 11yrs at the company I worked for,handled all batteries and warranty's.At the time we had Exide only then added the Optima when they came out.

Thats all I will say.....I KNOW NOTHING...