Originally Posted by InspGadgt

Yes it has to do with the height of the COG and the roll centers...but weight and where that weight is placed also play a large part of that. Think of the battery like the age old physics experiment of 2 bars of equal mass but different lengths...Hold each in the center and try to spin them, the shorter one is the easiest to spin. Now think of the battery like these bars, A battery crosswise on the chassis is going to be harder to get to roll, but once it rolls it is harder to stop, while a battery in-line will be easier to roll but also easier to stop.