I really know nothing about electricity... I am a retard when it comes to things of the sort. My friend is going to setup dual batteries in his 72 and was talking about finding the simplest way to do it. While in the discussion, one guy says that if you hook 2 batteries together (+ to + and - to -) that it doubles your battery amp output... for instance if you had 2 500 CCA batteries that you would now have 1000 CCA's? I was thinking that you would still have 500 CCA's, but have 500 CCA's for twice as long... What REALLY happens when you hook 2 batteries together like this?