Lose the zero...If a portable required 500W or 35+A at 12v or 5A @ 100v
those leetle batteries wouldn't last through the throes of booting W98 out
the door and into the trash bin.

Maybe 10W or ... a 3500MAH battery at 12V is only gonna give you 40W for an
hour.  Its all about Joule'ry.  Most oldtimey MMX portables will run for two
hours on 11 v and 4.2AH.  Convert Joules to watt-seconds and you'll see.

RVC (that 90A alternator is not spec'd for continuous duty at engine
compartment temperatures.)

p