Ok, so what's the difference between an auto and deep cycle battery? Which is better? The auto battery has a longer warranty and has more cranking amps, so why is the deep cycle more?? Is it just cause it can be submerged and still work, or is it because its a marine battery? If the battery is submerged I think I'll have more problems then getting my truck to start

exide orbital deep cycle
exide orbital auto

Is the general rule, the more cranking amps the better? Or is there some equation of cranking amps to lifecycle etc. that I should know about.