With the car running the battery goes from 13.7-13.9 (that's idling at 1400 rpm). I didn't look at it while not running or with any power options. Alternator is brand new. Kind of got stuck between a rock and hard place when the system was installed. One person installed it then found alot of teh wiring issues, we had to by pass some stuff so I could get it home because I was moving from NC to MA in 4 days and needed to put it on a truck to ship. Once up here a very reputable mechanic and chrylser specialist installed the new wiring harnesses with new alt, voltage regulator, distributor and ignition box.