Battery Voltage Issue
Thread Starter
Cruising
Joined: Sep 2019
Posts: 12
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Battery Voltage Issue
Good Morning,
2009 Base C6. I recently got my alternator and battery replaced and I have some questions regarding the battery voltage that reads in the dash. When I’m driving around the car is around 14.0-14.2 and when my car is just sitting there running it drops down to the 12s but this morning I started my car and was at a traffic light when I noticed it dipped all the way to the 10-11. I’m just curious on if this this normal or if there is a bigger issue. Like I said new OEM alternator and battery on the car.
update: driving it to work today in traffic I noticed it dips to mid 13s to high 12s when I’m just cruising with my foot off the gas.
2009 Base C6. I recently got my alternator and battery replaced and I have some questions regarding the battery voltage that reads in the dash. When I’m driving around the car is around 14.0-14.2 and when my car is just sitting there running it drops down to the 12s but this morning I started my car and was at a traffic light when I noticed it dipped all the way to the 10-11. I’m just curious on if this this normal or if there is a bigger issue. Like I said new OEM alternator and battery on the car.
update: driving it to work today in traffic I noticed it dips to mid 13s to high 12s when I’m just cruising with my foot off the gas.
Last edited by Daniel Jiwani; Sep 11, 2019 at 09:11 AM.
Drifting
Joined: Aug 2004
Posts: 1,709
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That sounds off. I was curious how the alternator and battery were doing on my 2006 base. Bought the car last year and the date code on the battery is August 2016. The battery AC Delco, showed 12.2 volts with the motor not running. I started the car, and idling it was 14.6 volts. This seems normal to me.
Last edited by Trebor; Sep 11, 2019 at 09:14 AM.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 413
From: WV
At startup with a stock alternator these cars should have around 14.4 to 14.6 volts. When running around, the voltage will slowly drop down to around 14 to 14.3 as the car warms up.. When my car battery is fully charged and it's a very hot day, my car sometimes goes down as far as 13.8, but never any lower...If your car is in the 12s then something is wrong.... Check all connections and make sure they're tight and clean of corrosion.. Check the alternator for output , it should be a little higher then the dash gauge shows...Check the battery ,at full charge it should be at least 12.6 or higher... Just because something is new , doesn't mean that it's working properly.....WW
Last edited by WW7; Sep 11, 2019 at 09:24 AM.
Thread Starter
Cruising
Joined: Sep 2019
Posts: 12
Likes: 1
Yeah the battery voltages were running fine after the initial install. I was getting around 14+ when driving and idling it would be in the 13s but today it was just very low. Some background on the car was the one day last week it wouldn't start which is why i replaced the alternator and the battery( which is what the mechanic said was wrong with the car along with the battery). Hypothetically if I check both the alternator and the battery and they came out fine what other components could be causing this issue?
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 413
From: WV
If its not the battery or alternator , my next guess would be wiring and connectors..You have to work your way through the system starting with the alternator and ending with the battery to check the wires and connections for 14 plus volts...If your getting 14.5 at the alternator and 14.3 or 14.4 at the battery wires then the battery would be bad or have a bad cell...WW
Last edited by WW7; Sep 11, 2019 at 03:36 PM.
Thread Starter
Cruising
Joined: Sep 2019
Posts: 12
Likes: 1
Update: turn out the custom sub and amp i had in the car from the previous owner was connected to the main battery and that was cause the issue. I ended up replacing the battery cables and the car has been running perfectly since with ideal voltage.
