This has probably been asked before, but I couldn't quite get the search to give me what I was looking for.

What is the proper voltage for a c5 as show on the dic while the car is running? I hear so much about battery issues and wanted to at least have some indication of when it wasn't charging properly.

Also, I heard that there were battery leaks on older c5 models that ran down into part of the computer system. Is this still an issue with the stock battery on a 2004?

Thanks

 

13.8 volts

 

No The newer cars are not effected. I'm told the problem w/ early Corvettes was caused from a robot that torqued the positive battery cable w/ excessive force. You should be fine w/ your '04. Good luck...

 

Mine shows 13.8 also.

 

Thats without Lights and etc on. Most always over 13.3

If you turn on your headlights you will see it drop to like 13.6 It should never be below 13

If your is the top mount battery you should be fine, it seems it was the side mount batterys that had all the trouble. I have an 04 as well and changed to an optima Yellow top. No battery does well if it sits for any period of time. Mine ran down several times, and it starts to weaken the battery. Also a battery tender plus, will keep your battery in tip top shape. Especially if you do not drive it often.

 

On the '97 - '00 cars - GM used a standard battery with side terminals. It is those batteries that leaked causing damage to the wiring harness and the PCM which is located directly below the battery tray. If you ever wondered what's there - take a look at this picture....



In '01, GM starting installing AGM (Absorbed Glass Mat) Batteries which is a sealed battery and resolved the leak issue, but by '03 it became apparent there was a problem with premature battery failure on that AGM battery, and it was discontinued by GM. In '04 - GM installed a top terminal standard lead acid battery, and so far I haven't read about leaking or premature failures.

There have been literally dozens of threads on the battery issues - and there is a strongly divided camp that reports no issues with any of the Delco batteries, others have reported catastophic issues with the leaking and premature failure. Still others claim the Optima Battery is defective and report multiple failures, still others insist that they bought a Die Hard from Sears or a battery from Wal-Mart and have had no issues.

So much depends on the environment like high ambient temperatures, high underhood temperatures, frequency of use, maintenance, etc. Obviously - a car in San Diego where the ambient temperatures are generally moderate, and the vehicle is driven daily - isn't going to experience the same rate of failure or type of failures as a car in the extreme heat of the desert Southwest for example, and a car that is a "weekend warrior" that is only driven occasionally. Heat is the biggest detrimental factor in premature battery failure.

As far as the question about what is the "normal" voltage on the DIC - I would think between 13.2vDC and 14.0vDC is normal. Less than that would make me be concerned that the battery was no longer holding a charge, or that the charging system itself was failing.

My opinions, of course.

 

I agree with the "I would think between 13.2vDC and 14vDC is normal. "

I am also one of the people who had problems with the Optima battery.
So now I just use a $40 Kirkland from Costco

 

Depending what accessories I'm running at the time, between 13.5 and 14.3 VDC.

 

I have an optima red top. After sitting for a week or so, the guage shows charging at 14.2. After driving for 15 or 20 minutes, it settles in at around 13.8

 

It appears that I am good all the way around. I appreciate all the great info everyone posted here.

Man I love this place

 

Anyone know what the voltage reading should be after the battery is on a battery tender for a 1-2 of months?
I recall one time on start-up the inside voltmeter read around 11.5.
It then went up to 13.8.
I wondered if running the car charges it up a little higher.

 

I had to replace my battery about a month ago, it died. I was getting low readings even with the new battery, so I took it to my mechanic and he checked the battery with the car idling with no accessories turned on in the car. the battery showed 13.8V while the DIC showed 12.1V , now I can't trust my DIC for voltage readings.

 

Guess I need to change my battery. I run 13.2 and with A/C 12.8.

 

Same readings with my stock AC Delco (for now )

 

i have an interstate battery with side post which came in the car .and it also shows 13.8

 

What you are seeing with the car running is alternator voltage. If you only want to see battery voltage -- key on, but engine not running.

 

Then what should be the normal for that setting? Mine is: 12.3 after sitting for an hour.

 

I would consider that normal battery voltage.

 

On the DIC, that voltage is fine. The DIC is designed to read alternator voltage with the car running, and it reads a slightly lower battery voltage when the car's off since there are other voltage drops in the circuit. If you put a digital voltmeter across the battery terminals, you'd likely see 12.66V, which is what a fully charged battery should be at.