by The Roadie » Sun May 02, 2010 3:22 pm
Deep cycle isn't the attribute to look for, although some batteries are good for starting AND deep cycle. But they're a compromise. The Die Hard name is applied to many Sears batteries, but (IIRC) only the Platinum uses the AGM (absorbed glass mat) technology to make it unspillable. Unspillable is a nice feature to have, and that technology (flat plate + AGM) is shared by the Odyssey high end batteries.
What the Optimas and Exide ORBITAL have is spiral-wound AGM plates, which wastes a bit of the battery volume, giving you fewer amp-hours capacity, BUT the huge advantage (to me at least) is the vibration resistance of the spiral wound ones. I had a friend in an old Suburban have his flat plate battery short out internally (!) on a Death Valley washboard. Almost lost the car in the ensuing battery meltdown. So I'm not changing from my choice of spiral-wound, although the recent reliability horrors of Optimas is going to make me lean toward an Orbital when I need a new one in the next 6-12 months. My current Optima was from the previous factory, and has been essentially worry free for 60K hard-bashing miles.