Originally Posted by garym1a2
Just to add one note, alternators are normally rated at 6000 alternator rpm, this is about 2000 to 3000 engine rpm depending on pully ratio. At low rpm that 150 amp alternator may only put out 100 amps.
So, if I am driving along at a "normal" cruise with the tach showing between 1000 - 1500 engine rpm then I should expect about 100 amps? Is that the low rpm range you mean.
The other question I would ask is, if the alternator has the capacity to put out 100 amps at cruise, how much of that is excess beyond the needs of the vehicle? I realize that will be dependent on a number of factors, but are we talking 50%, 25% or more in excess current available to drive other devices (radios in my case)?
Thanks for the information gentlemen,