Volt tester / Charging Questions

I am getting 35-40 volts at the Alt Stud, I am seeing lows 12's at the battery when running.The number gets lower aned lower everytime I start the car.

I was under the impression that anything under 12.6 volts at the battery at Idle is actually discharging. Both the Alternator, and the Voltage regulator I used are brand new (I have a cool parts Guy that will let me return them if need be).

I tested all my other vehicles and they all show around 14 volts while running, and roughly 12.6 when the car is off at the battery posts.

I really want to be able to be confident when going out for a cruise that It will start again.

I have long ago bypassed the ammeter.

I plan to hook up a voltmeter once I get things working right.