The Natural Philosopher was thinking very hard :
The alternator will deliver whatever voltage it meeds to but of course there
would not need to be a particularly large voltage to charge a battery that
is capable of delivering over 700 A to starter motors without crapping out

That is a rather odd statement. Some alternators output a maximum fixed
voltage, more modern ones vary the voltage slightly depending on
demand. Because a battery can deliver 700amps does not mean they are
capable of accepting 700amps as a charge current. The 700amps is for a
very short period of time.




I would suggest nearer an initial 20amps, which would rapidly fall to maybe
3 to 6 amps. A flat to full charge time when being driven, can require 6 to
10 hours of being driven. Which is why it is always best to put such a
battery on a mains charger for 24 hours, if at all possible.


Total crap. There is no pint in having a 150A capable alternator to do THAT

The point of having such a large potential current output available, is
nothing to do with putting that current into the battery - it is there
to cope with the massive current demand of lights, cabin fans, cooling
fans, screen heaters and etc.. My cooling fan at maximum demands
50amps.

I tell you again - you need a much larger voltage difference between
the battery and the charging supply, to get an effective, high current
rapid charge into a battery. Such a high voltage would burn lamps out
and electronics.