Battery Voltage Question
Thread Starter
Intermediate
Joined: May 2003
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From: long Beach Ca
Battery Voltage Question
I have a 07 C6 Z51 I have noticed the Battery volts when driving at 2000 RPM is at 14.5 volts . Drove 50 miles voltage stays the same. I thought as the battery charges the alternator output voltage should drop. Anyone have any ideas. Or do I have a bad battery ?
Last edited by vettman6; Apr 5, 2010 at 12:50 PM. Reason: misspell
Team Owner
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From: Southern Utah
14.5 is normal. When driving around you are looking at alternator voltage not battery voltage, battery voltage is only shown when the engine is off.
Last edited by cclive; Apr 5, 2010 at 01:53 PM.
Team Owner
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From: McKinney TX
St. Jude Donor '21-'22-'23-'24
I saw this thread before I made a 150 mile drive today, so I occasionally checked the battery voltage during the drive.
For the first 75 miles driven one way, 50 miles of which was on the interstate at 75 to 77 mph, the voltage was constant at 14.3. When I started back, the voltage was reading 14.2 and stayed at that value until I got about 3 miles from home and got into 35-45 mph stop and go traffic. Then the voltage dropped to 13.7 to 13.8 until I stopped the car and shut off the engine.
My 06 C6 coupe does have the F55 suspension, with no Nav and no On-Star.
For the first 75 miles driven one way, 50 miles of which was on the interstate at 75 to 77 mph, the voltage was constant at 14.3. When I started back, the voltage was reading 14.2 and stayed at that value until I got about 3 miles from home and got into 35-45 mph stop and go traffic. Then the voltage dropped to 13.7 to 13.8 until I stopped the car and shut off the engine.
My 06 C6 coupe does have the F55 suspension, with no Nav and no On-Star.
Last edited by Vette_DD; Apr 5, 2010 at 08:11 PM.
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Team Owner
Joined: Mar 2008
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From: Southern Utah
Since we now have digital readouts that show the voltage to a tenth of a volt, we are seeing differences in the voltage and thinking they are significant when they are not. Half a volt would not have even shown up on an analog volt gauge of the past. The difference between 14.5 and 13.8 is just not important, even though our fancy digital readout makes it appear to be so.
Team Owner
Joined: Oct 2004
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From: San Clemente CA
Since we now have digital readouts that show the voltage to a tenth of a volt, we are seeing differences in the voltage and thinking they are significant when they are not. Half a volt would not have even shown up on an analog volt gauge of the past. The difference between 14.5 and 13.8 is just not important, even though our fancy digital readout makes it appear to be so.
Some auto's don't have a volt meter, just a red light if it's not charging. My XJ8 only has a light. 
Burning Brakes
Joined: Apr 2007
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From: New Bern NC
Yes, what is correct?
I've been thinking about this one since I saw it yesterday. I know more about boat stuff and from my boat electrical experience, the smart regulators do drop alternator charging voltage as the battery reaches a full charge. I always seem to see the same response on my GMC pickup analog voltmeter; the initial voltage is always more than it is after driving for a while. I assume there must me some sort of smart voltage regulator in the system or we would fry our batteries. But, my Vette always seems to have higher voltage, 14.2-14.4, than my pickup. And, the voltage does not seem to drop very much. I suppose the German luxury cars have a good point in not providing anything except coolant temp; that way we cannot obsess about the numbers.
Larry
Larry
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An interesting article on fluctuating voltage is posted at :
http://www.daytondailynews.com/dayto...=rss_auto-news
http://www.daytondailynews.com/dayto...=rss_auto-news
Melting Slicks
Joined: Jun 2007
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From: Upstate New York
An interesting article on fluctuating voltage is posted at :
http://www.daytondailynews.com/dayto...=rss_auto-news
http://www.daytondailynews.com/dayto...=rss_auto-news
