Here's how I learned it in engineering school when I got my degree in electrical engineering...

RE:"voltage is controlled by a regulator,if voltge was allowed to climb,fuses would pop....amperage is a little different,".

Amperage is what "pops" a fuse. Regulators are rarely fused and many have internal current limiting circuitry. Voltage rise per se will not pop a fuse directly, only insomuch as the increase in voltage causes a high current to flow.


RE:"the amperage is gonna be the same in a circuit,again,menaing,this charging system and the batteries,the amperage flowing in this circuit is the SAME THROUGH OUT."

Not true ( according to my DC circuit analysis class )... You can have one current flowing from the regulator towards the batteries ( its limited by the regulator and/or the capacity of the alternator to deliver current) and another different current flowing between the batteries..

I REPEAT... the current flow BETWEEN paralled batteries is totally "uncontrolled" (i.e. by any external control device) and the current BETWEEN them is limited mostly, (if you ignore the source impedance of the batteries) by the difference in the voltages of the two batteries and the resistance of the cables and switch contacts. It is entirely possible to generate enough of a current flow to distort the battery's plates... and cause...a shorted cell!