A CR123 battery is fairly weedy, you want to try flying with one of the C-cell sized ones. 7AH capacity and capable of all sorts of spectacular things if something goes wrong. Even better, shipping a box (or several boxes) of 180 units each containing such a battery. Fortunately I wasn't the one who had to do the paperwork.
When taking single items with lithium batteries on passenger flights, I think having them in the cabin is preferred, simply because a fire can be handled more easily than if it's under the floor.