That's correct. My 160 amp alternator is cold rated at 160. At operating
temperature (too hot to touch) it only puts out around 135 or so. The
160 figure is really a marketing figure.

Doug
s/v Callista

"Skip" wrote in message
om...
Tim wrote:

Doug Dotson wrote:

You need to learn more about the requirements of a marine
charging system. Alternator requirements have only little to do with
loads directly supported by the alternator. High charge rates are

used to

recharge a large battery bank in a short period of time.




Doug, I'm glad you reminded me of that. I've run a starter/alternator
shop for the last 23 yrs. and maybe I missed something along the way.

Whether on a "marine" application, a 73 toyota corona, or a greyhound
bus, you have batteries, an alt/gen, a regulation system, and a
.....load.

inverters, split voltages, hi/lo amp settings, DUVAC, etc, are all in
between.

The products you utilize in this situation is the key...

I suppose what I'm saying is, that you can buid a 350 chevrolet engine
and say "This things got 450 horsepower, You don't need that Cummins to
pull that 52 foot van trailer"! .. and in theory, that's true. But in
practicality..its waning badly.


This might be where you are BOTH right...
It has been a while since I looked, my memory is that the ratings on
alternators is not standard.
It seems there are derating curves by manufacturer/model - 100 amp rating
is seldom (never?) continuous 100a.
Ya gotta read the fine print - sometimes not even on the box with the
alternator inside.

My bet is that the alternator will work for a long time ONLY when ALL the
conditions are met.
That includes what you all have been talking about, plus more obscure
factors like ambient temp.

That's 2 cents.
Skip