Battery level...Is this normal?

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Jun 23, 2013 | 05:59 PM

cedp83

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Joined: Jun 2011

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From: Estero, Florida

Battery level...Is this normal?

I just noticed this today and I was wondering if this is normal....
While I was stopped waiting at a red light I noticed my battery level voltage under 13... (radio on and a/c running )

while driving it goes back to 14, 14.5...

Is this normal?
Is my battery dying? (1 yr old)
Alternator going bad?

Jun 23, 2013 | 06:01 PM

LS WON

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Joined: Dec 2002

Posts: 32,074

Likes: 296

From: San Francisco CA

Quote:

Originally Posted by cedp83

I just noticed this today and I was wondering if this is normal....
While I was stopped waiting at a red light I noticed my battery level voltage under 13... (radio on and a/c running )

while driving it goes back to 14, 14.5...

Is this normal?
Is my battery dying? (1 yr old)
Alternator going bad?

Jun 23, 2013 | 06:46 PM

Mad*Max

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Joined: Apr 2007

Posts: 16,025

Likes: 1,656

From: Toronto, Canada

C7 of the Year - Unmodified Finalist 2021

whether this is normal or not my car does the exact same thing for the last 3 years (at least) that I have noticed

Jun 23, 2013 | 06:56 PM

EvanD

CF Community Team

Joined: Nov 2005

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From: Charlotte N.C.

Mine never goes below about 13.5V

Jun 23, 2013 | 07:11 PM

RnLi

Burning Brakes

Joined: Mar 2008

Posts: 815

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From: Mesa "highlands" AZ

My OEM battery is on 5 years. The car is a garage queen and I use a battery maintainer on occasion (when going on vacations, etc.). I have never witnessed my volt gage under 14.......including at night with lights, a/c and radio operating.

Jun 23, 2013 | 07:15 PM

LS WON

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Joined: Dec 2002

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From: San Francisco CA

Quote:

Originally Posted by RnLi

Mine is original 2005 battery and it does drop into the 13 range. Before it went as low as 12.9 but for the most part is between 13 to 14.5.

Jun 23, 2013 | 07:26 PM

Mad*Max

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From: Toronto, Canada

C7 of the Year - Unmodified Finalist 2021

mine goes down to 12v when stopped at a light (mine is auto) with the a/c on as the engine fan is on continuously and my suspicion is that it draws a lot of power

Quote:

Originally Posted by LS WON

Mine is original 2005 battery and it does drop into the 13 range. Before it went as low as 12.9 but for the most part is between 13 to 14.5.

Quote:

Originally Posted by RnLi

Quote:

Originally Posted by EvanD

Mine never goes below about 13.5V

Jun 23, 2013 | 07:29 PM

MikeyTX

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From: Big Bend Country, TX

St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21

NCM Lifetime Member

Have you checked the water level in the battery ? The factory unit is not a sealed unit. The caps do come off so you can add distilled water.

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Jun 23, 2013 | 07:30 PM

hdkeno

Melting Slicks

Joined: Nov 2010

Posts: 2,436

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From: CT

My 06 has a new delco battery in it. Usually is at 4.2-4.5 but i did see it momentarily drop to 13.0-13.2 at idle everything on and ac

Jun 23, 2013 | 07:38 PM

#10

Pinky...

Melting Slicks

Joined: Jul 2008

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Honestly, this is not an accurate way to really gauge performance of the Alternator and Battery. You need to first verify the battery is fully charged and is a known good battery. Then you would need to load test the alternator to see if it is putting out proper voltage under load.

Jun 23, 2013 | 07:44 PM

#11

Mad*Max

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From: Toronto, Canada

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I put a new OEM battery 12 months ago and as I mentioned my car has been doing both before and after the battery change

Jun 23, 2013 | 07:46 PM

#12

VET4LES

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From: San Clemente CA

Its normal. Put the battery reading on your DIC and get an accurate reading.

Jun 23, 2013 | 07:47 PM

#13

LS WON

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Joined: Dec 2002

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From: San Francisco CA

Quote:

Originally Posted by MikeyTX

Have you checked the water level in the battery ? The factory unit is not a sealed unit. The caps do come off so you can add distilled water.

tHIS Is true I have done this.

Jun 23, 2013 | 07:59 PM

#14

c54u

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Joined: Aug 2006

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Quote:

Originally Posted by cedp83

Is this normal?
Is my battery dying? (1 yr old)
Alternator going bad?

Mine is a 2007 and it did the same thing as yours a few years ago. I replaced the serpentine belt with a Goodyear Gatorback and presto the voltage stayed in the high 12's at idle and high 14's driving.

I would check the tensioner, and belt....easy stuff first. The belt was only 25 bucks and takes 5 minutes to put on.

Jun 23, 2013 | 08:05 PM

#15

Gearhead Jim

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From: Far NW 'burbs of Chicago

St. Jude Donor '13

Our 2009 has 60k miles and the battery was replaced just as a precaution, a year ago.

The voltage displayed on the meter or on the DIC has always varied considerably; depending on electrical loads, rpm, temperature, and probably several other items I'm not aware of.

Jun 23, 2013 | 08:12 PM

#16

dvilin

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From: Rochester, NY

Mine has never gone below 13.5.

Jun 23, 2013 | 08:21 PM

#17

Rogers 07

Drifting

Joined: Jun 2008

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From: Jupiter Fl

This is normal, at idle on a warm day when the electric cooling fans come on, along with the AC etc, it will pull the voltage down towards 12. To check, just rev the engine a little bit to 1000 RPMs or so and the Voltage should go back up to 13+ Volts !!

Jun 23, 2013 | 08:34 PM

#18

cedp83

Thread Starter

Instructor

Joined: Jun 2011

Posts: 116

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From: Estero, Florida

ill check the water level first...how do you know a tensioner is bad??? I can replace the belt..no problem...
BTW the battery is a Napa legend 75 (POS???)...
and the problem behind this is...my Kenwood headunit "senses" the voltage drop and goes into "safe or protection mode" so no more radio...
maybe I need a yellow top???

Last edited by cedp83; Jun 23, 2013 at 08:36 PM.

Jun 23, 2013 | 09:09 PM

#19

c54u

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To check the tensioner

With the belt off the tensioner, spin the tensioner pulley and see that it spins freely. Put the socket wrench back on the tensioner that you used to remove the belt and move the tensioner back and forth to make sure that it moves freely back and forth. There should be smooth resistance when moving the tensioner back and forth.

Jun 23, 2013 | 09:11 PM

#20

VET4LES

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Joined: Oct 2004

Posts: 27,420

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From: San Clemente CA

Quote:

Originally Posted by cedp83

The yellow top could be just what you need due to your sound system. Check out the Optima web page and see what they say about it. The yellow top is for deep discharge use.

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