> 4 - What is the battery voltage during cranking?---USED SUPPLEMENTAL
BATTERY AS WELL
A supplemental battery won't cut it. I made the same mistake once
with a buddy's BMW--the battery was questionable, but the car was
cranking fine, so I thought that hooking a up another car (via jumper
cables) with a good battery, and running it at 2000RPM would ensure
that the dead car would have more than enough juice to start--not so.
The bad battery can drag down any sort of supplemental power source
you hook up. In the afformentioned BMW case, a new battery solved
the problem.