[curtis73]

You're right, the car runs on juice from the alternator. The battery is just a storage facility. Usually there are only about 20 amps being used in a typical car while its running and many of today's alternators are capable of supplying 100 or more. I think that Ram truck has a 140 amp alternator. For this reason the deep cycle may not be the best choice. Deep cycle batts don't like it if they're not being deep cycled, and even with heavy draw items like hydraulic pumps, it would only cycle about the top 10% of the battery's capacity with the truck running.

I've had good luck with Optimas (the non-deep cycle), Interstate, and anything made by Exide. They often are sold under the Energizer name, NASCAR brand, or others. Look on the battery's label and somewhere it will say Exide if its their handywork.