Bartamos to answer all your questions .. yes it’s a true one wire alternator from shop 10Si. I’m running a 12volt system with a 216 motor . By smslller type battery just meant it’s not a average size it seems to be Smaller housing than avg but it is rated at 640 CCA and 800CA .. that was my wonder why am I pulling 36 volts from altenator at idle speed and 13v at battery ? I’m going to make sure my alternator is getting a good ground before anything else seems to be every one who replied suggestion. Thanks for the reply