The stator for 4-tecs is rated at 380 Watts each I believe, some portion of that is consumed by the engine control system.
Crank-starting most any engine consumes power thus typically can take 20 minutes to recover a battery from discharge lost during cranking, regardless of alternator capacity due to lead-acid batteries have large hysteresis(this knife cuts both ways, no free rides).
Sometimes that can be avoided, but probably not in many cases:
