Taking advantage of the unique aspects of organic processing would have made way more sense than our convoluted and comparatively inefficient, especially in context, power output. Also closes the loop, at least somewhat, on "why didn't they make people vegetables."

Oh god, that sounds so much better than the battery idea. But yeah I could totally see regular audiences not being able to understand that. Morpheus really succinctly summed up his argument when he just pulled out a AA battery in that scene. Such a good movie moment.