PEWTRESS, NATHAN JAMES III City/State: St George / UT PCF Number: 195766 Arrest Date: 19:22:00 02/01/18 Agency: St George Police Department RELEASED FROM CUSTODY
then you need a little more rpm to get the alternator to charge above the battery voltage. About 13.5 volts. The average alternator is now between 1,300 to 2,100 rpm. I set up an old 35 amp alternator to run off a 1/3 hp 1,750 rpm washing machine motor at a 1:1 belt ratio. Using the stock regulator would stall the 1/3hp motor. I put a large adjustable resister on the field connection of the alternator.
If you allow the car to drive around and I think it will eventually put the charge back in the battery. Here's a chart showing some auto alternator curves. If you run the car at cruising speed (not idle) then you will hit 1500 RPM or more and this chart indicates you can get 50, 100, or more amps from it. Even if you get 50Amps a typcail car battery is maybe 60 Amp hours so you could charge the whole bettery with an hours driving.