Alternator Condition

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chunji08@gmail.com - 20 Jan 2006 01:01 GMT

Hi Forks,
I have a Volvo 850 wagon, which is of year1996 and has 90K on it. I
have just had the battery replaced and yesterday I did some testing to
see how good is my alternator.
Following are my test results:
1.If the engine is not turned on, the voltage read from the battery is
12V.
2.If the engine is turned on and RPM to 1500, the number is 13.6V.
3.If the engine is turned on, along with air condition, radio and
head-lights, the number is 13.4V.

So What do you think the condition of that Alternator ?

thanks,

Charlie

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Al Bundy - 20 Jan 2006 12:36 GMT

I don't know whether your equpment is accurate. If you measured an
accurate 12.0 volts (assuming above freezing temps) then your battery
is under charged or defective, regardless of its age. The 13.4V-13.6V
readings are marginal. So if the vehicle starts and keeps everything
charged, perhaps your meter is reading low. It would be my guess that
your meter is reading a half volt low.

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CL (dnoyeB) Gilbert - 20 Jan 2006 13:44 GMT

> Hi Forks,
> I have a Volvo 850 wagon, which is of year1996 and has 90K on it. I
[quoted text clipped - 12 lines]
>
> Charlie

I don't see how these tests are testing your alternator. You would need
an ampmeter. Of course I think your battery should be reading ~13.5V
when the engine is off. Especially considering its brand new.

Where are you reading the voltage?

--
Thank you,

CL Gilbert
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

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N8N - 20 Jan 2006 14:21 GMT

> > Hi Forks,
> > I have a Volvo 850 wagon, which is of year1996 and has 90K on it. I
[quoted text clipped - 18 lines]
>
> Where are you reading the voltage?

At the battery, he should be reading about 12.6V with the key off.
With engine running I would like to see 13.7-14.7V.

nate

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joshua@bohannonbattery.com - 20 Jan 2006 15:19 GMT

The battery should definately read 12.5 to 12.7 volts to indicate a
full charge. Typically an alternator will read anywhere from 13.6 to
14.6 if it is working correctly.

If your battery set on a shelf for several months before you bought it,
its possible it discharged to 12 volts. You would simply need to place
it on a trickle charger on 2 amps overnight to bring it back to a full
charge.

Of course with the vehicle running, and the lights and AC on you will
have somewhat of a voltage drop. 13.4 is low, but not to the point
where I would recomend buying a new alternator or having your current
alternator rebuilt.

And you have to keep in mind as the vehicles engine is revved up, the
voltage the alternator supplies will increase.

Joshua
http://www.BohannonBattery.com

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