Just replaced my alternator. Broke down on the road, dead battery but it is brand new. I suspect that I have an excessive electrical drain which caused this failure. Best method to solve this. I realize that after the car has shut down the draw on the battery should be around 40 milli amps, is this correct?

 

If you are measuring Amps then it is a pretty long process.
You need to wait about 15 minutes it drops in stages till it reaches about .50 Amps.

If you replaced the Alt and it died after that than it sounds like it isn't charging.