Well, a little research revealed the reason for connecting the sensor wire right to the battery terminal. Line loss. If you have a heavy draw on the battery the line loss of a normally sized charge wire from alternator to battery will give the wrong info to the internal regulator, since many are wired with a gauge for average charging, not heavy charging. That creates a difference in what the regulator seesUNLESS you use a very good charging line. I am using #4 welding cable, for virtually zero line loss. That allows me the ability to connect the sensor wire at the alternator charging lug.