battery getting drained while driving

OK,had a chance to check things out again.Batt was at 12.80 volts.started car on choke.1800 rpm batt droped to 12.08 and same at alt charge post.turned car off and removed the alternater charging wire.restarted car-1800 rpm.alt showed 1.39-1.40 volts.The new alternater is bad or built on reg in bad. called summit-they are going to warranty with a new one. when I first installed the alternater was getting 14.7 with both fans on.