On Thu, 11 Jul 2019 22:02:05 +0100, The Natural Philosopher
wrote:

On 11/07/2019 14:47, Xeno wrote:
On 11/7/19 5:11 am, Commander Kinsey wrote:
Well I see the full voltage charging a flat battery at idle.
Obviously they could be designed to be capable of this and it would be
very useful to charge the battery quickly when doing stop start town
driving, or driving at minimum revs in top gear in a town.

You may see a high voltage but you will not see a high current at idle.
The alternator is not *capable* of high current at idle.



You would be surprised.

Howver 80A at 12v is only a brake horsepower and a bit..





On Sun, 23 Jun 2019 07:07:14 +0100, Xeno
wrote:

On 23/6/19 5:47 am, Commander Kinsey wrote:
Modern car alternators seem to be able to give out a huge amount of
current at engine idle speed.* I'm sure my friend got his to give out
pretty much the full 80 amps without revving the engine.* He was
powering a small disco on a campsite :-)

No way to get a full 80 amps out of an alternator *at idle*.

That however is probably true for most car alternators


The ADVANTAGE of an alternator is it CAN produce full output at low
RPM. (compared to a DC generator)

What an 80 amp alternator has trouble with in many cases is producing
that power at low speeds without melting down (due to reduced cooling
air flow at low speeds)