[Neidermeyer]

Bingo!
Automotive alternators in general are about 40% effecient.
The big generator heads your see on standby gen-set are approx 92 - 94% efficient.
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The alternator on your car makes AC power ,, same as your standby genset ,, however in the car one half of the “AC waveform” is discarded to create DC current ,, therefore the most efficient a car alternator can be is 50% efficient if it was “perfect” ... now if you could tap into the current before the diode in the voltage regulator discards half your electricity and you use the wasted electricity then you have recaptured energy.

[John Jamieson]

“however in the car one half of the “AC waveform” is discarded to create DC current ,, therefore the most efficient a car alternator can be is 50% efficient if it was “perfect””

Your ignorance of science is astounding. please stop posting BS like this, your making my brain hurt.

[thackney]

Modern automobile use full wave, three phase rectifiers.

[Tallguy]

Don’t AC waveforms get rectified these days rather than simply clipped by a diode? Using a rectifier would give you the entire waveform to work with, not just half.

[Old Professer]

Good site, diagrams, explanations, etc:

http://www.bcae1.com/charging.htm

[Rick.Donaldson]

negative. Those half cycles aren’t discarded, full wave rectifiers are used. That means the missing half cycle is actually used...