While doing some googling to find out why the voltage of my pickup truck pulses at idle, I came across a web site that has excellent explanations about some aspects of automotive electrical systems, with particularly good information about charging/alternator systems. Some of this might be a good starting point to figure out how to have an high-output alternator without cooking a standard-size battery in our Valkyries. of particular interest to me was the "Chevy Main Electrical Power System" article.
http://www.madelectrical.com/electrical-tech.shtmlYour quest can be answered in very simple terms as it has been stated in previous posts.
Somewhere in your search to understand by reading articles you may find that the charging of the alternator needs to match the output of the battery in which is controlled by the voltage regulator to do so. The reasoning behind this is very simply stated as:
The need to feed the many or the few power requirements is why they even very as such.
