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https://www.autonerdz.com/cgi/yabb2/YaBB.pl General Public Area >> For Non-Technicians >> Starter has a Peak of over 700 A https://www.autonerdz.com/cgi/yabb2/YaBB.pl?num=1322414153 Message started by Christian on Nov 27^th, 2011 at 9:15am

Title: Starter has a Peak of over 700 A
Post by Christian on Nov 27^th, 2011 at 9:15am

Hi,

I Just did a Test on my Starter (Audi A3 2005 FSI) and Battery,
just to see if anything could drop out over the coming Winter.

Is this really o.K ?? Its just a 1,6L Engine....

The Battery and Cables seem o.k, i expected max about maybe
300 A or something like that for this little Engine.

Because i couldn´t believe it, i did a Diagnostics-Test also,
with about the same results....

Chris

https://www.autonerdz.com/cgi/yabb2/YaBB.pl?action=downloadfile;file=Starter.psdata (233 KB | )

https://www.autonerdz.com/cgi/yabb2/YaBB.pl?action=downloadfile;file=111127_StartTest_005.pddata (577 KB | )

Title: Re: Starter has a Peak of over 700 A
Post by Spence on Nov 27^th, 2011 at 9:25am

Hi Chris, If you are talking about the intial hit when the starter is engaged then I would feel this is normal. I for one would like to see a longer cranking time if you could to get a better idea of things when testing.

Thanks for posting your findings

Spence

Title: Re: Starter has a Peak of over 700 A
Post by Kevin J on Nov 27^th, 2011 at 12:38pm

Hi Chris, the initial draw can be high for a very short period of time. I've seen other 4 cylinder engines up about 650 amps. The thing with Pico is that you can measure those high currents which occur for only a very short period of time.

The other thing I took from the test is the battery performance. It’s in the green which to me tends to indicate that the starter load is matched to battery size. If the battery is still as per manufacturer specs then this is another indication that the current draw is probably fine, as the battery is coping with the load. Also the internal resistance of the starter is in the green.

In the end if there are no problems then in all probability its fine.

Regards
Kevin :)

Title: Re: Starter has a Peak of over 700 A
Post by Christian on Nov 28^th, 2011 at 1:05pm

Hi,

Thx for the answers.Yes, Battery is which it should be.
It came new last Winter.The old one did have some Problems
in the Morning sometimes.And before the cold days come
and i see myself looking for another car to jumper mine
i just wanted to look at that, and i just thought it is a little bit
strange, even if its just for a very short time.

I will do another test when i get time for that and also
with a newer one, just for the intresst what they "pull".

Chris

Title: Re: Starter has a Peak of over 700 A
Post by Red on Jan 18^th, 2012 at 1:30pm

Christian, I've seen starters for 1.6L engines referred to as "kilowatt" and "one and a half kilowatt" so 700A would seem excessive, even for a short term. Of course those numbers are with analog meters not scopes, perhaps your "700" is a very short interval and needs to be put in a longer perspective for an averaged number?

Title: Re: Starter has a Peak of over 700 A
Post by crackerclicker on Jan 18^th, 2012 at 6:33pm

Red wrote on Jan 18^th, 2012 at 1:30pm:

perhaps your "700" is a very short interval and needs to be put in a longer perspective for an averaged number?

this is exactly right, and very easy to see on a scope. here's a crappy capture of a 5.2l chryco product that has an initial in-rush of 596 amps with an average of approx 159 amps.

starting_current.JPG (58 KB | )