[cmking26]

My voltage meter on the dash is usually reading around 12 volts, seldom does it show 14. Is this normal for these cars? I'd guess it reads 12 about 60% of the time. Sometimes even at cruising speeds or accelerating it still shows about 12.

[Glen e]

yes normal...google intelligent charging, it does not charge unless the batt needs it.

[17rsvert]

Mine reads 12.1 volts most of the time when driving, which concerns me because my battery is not staying fully charged. I had the battery hooked up to my Schumacher smart charger every night last week. The car sat unused without the charger over the weekend, and when I checked the voltage (Fluke multimeter) Sunday night it was 12.52. The next day (without using it or even opening a door) it was down to 12.41 volts. The next day I drove to work and back 1/2 hour each way, and when I got home, checked the voltage again with the car shut off and it was 12.25 volts. That night I charged the battery again overnight and disconnected it in the morning. Car sat unused all day, I drove my beater jeep to work. When I got home the battery read 12.85 volts. It does not seem that the intelligent charging system is too intelligent.
By the way, the car sat unused for a week last month and the battery was dead (4.50 volts) I managed to charge it, took it to the dealer, and the service tech told me the battery is good, charging system is good and the parasitic draw is 0.2 milliamp, which is within specification. None of this makes any sense.
Anyone else having problems like this?

[cmking26]

Originally Posted by Glen e

yes normal...google intelligent charging, it does not charge unless the batt needs it.

AHHHH makes sense. Thanks

[Rock-It Man]

Originally Posted by cmking26

My voltage meter on the dash is usually reading around 12 volts, seldom does it show 14. Is this normal for these cars? I'd guess it reads 12 about 60% of the time. Sometimes even at cruising speeds or accelerating it still shows about 12.

The voltage displayed on the dash is the charging voltage, which varies depending on the state of charge of the battery.

Originally Posted by 17rsvert

Mine reads 12.1 volts most of the time when driving, which concerns me because my battery is not staying fully charged. I had the battery hooked up to my Schumacher smart charger every night last week. The car sat unused without the charger over the weekend, and when I checked the voltage (Fluke multimeter) Sunday night it was 12.52. The next day (without using it or even opening a door) it was down to 12.41 volts. The next day I drove to work and back 1/2 hour each way, and when I got home, checked the voltage again with the car shut off and it was 12.25 volts. That night I charged the battery again overnight and disconnected it in the morning. Car sat unused all day, I drove my beater jeep to work. When I got home the battery read 12.85 volts. It does not seem that the intelligent charging system is too intelligent.
By the way, the car sat unused for a week last month and the battery was dead (4.50 volts) I managed to charge it, took it to the dealer, and the service tech told me the battery is good, charging system is good and the parasitic draw is 0.2 milliamp, which is within specification. None of this makes any sense.
Anyone else having problems like this?

If your battery is dead after sitting a week, either your battery is damaged or you have added some accessories that continue to draw current when the car is not running...or both.

[chrest]

Originally Posted by 17rsvert

Mine reads 12.1 volts most of the time when driving, which concerns me because my battery is not staying fully charged. I had the battery hooked up to my Schumacher smart charger every night last week. The car sat unused without the charger over the weekend, and when I checked the voltage (Fluke multimeter) Sunday night it was 12.52. The next day (without using it or even opening a door) it was down to 12.41 volts. The next day I drove to work and back 1/2 hour each way, and when I got home, checked the voltage again with the car shut off and it was 12.25 volts. That night I charged the battery again overnight and disconnected it in the morning. Car sat unused all day, I drove my beater jeep to work. When I got home the battery read 12.85 volts. It does not seem that the intelligent charging system is too intelligent.
By the way, the car sat unused for a week last month and the battery was dead (4.50 volts) I managed to charge it, took it to the dealer, and the service tech told me the battery is good, charging system is good and the parasitic draw is 0.2 milliamp, which is within specification. None of this makes any sense.
Anyone else having problems like this?

I am.

i cant let the car sit a week without it being dead. i need to get it into the dealer to get it replaced. its been doing this since i got it. If i drive it daily, i never know its a problem until about 7-10 days.

[17rsvert]

Originally Posted by chrest

I am.

i cant let the car sit a week without it being dead. i need to get it into the dealer to get it replaced. its been doing this since i got it. If i drive it daily, i never know its a problem until about 7-10 days.

Please let me know what the dealer test results are. From my limited experience and reading related posts, I have a feeling that the dealer test equipment does not tell the whole story about the either the condition of AGM batteries, parasitic draw, or performance of the charging system. Way too many batteries are going dead too soon.

[TedJS]

Originally Posted by 17rsvert

Please let me know what the dealer test results are. From my limited experience and reading related posts, I have a feeling that the dealer test equipment does not tell the whole story about the either the condition of AGM batteries, parasitic draw, or performance of the charging system. Way too many batteries are going dead too soon.

Dealers use a GR8 to test the batteries. It's very accurate. http://www.midtronics.com/shop/produ...ttery-chargers

Charging system is tested by a scan tool. Only way to full field generators on modern systems.

[17rsvert]

Originally Posted by TedJS

Dealers use a GR8 to test the batteries. It's very accurate. http://www.midtronics.com/shop/produ...ttery-chargers

Charging system is tested by a scan tool. Only way to full field generators on modern systems.

It doesn't matter how high tech the test equipment is if the techs can't get to the root cause of the problem. Dealers keep telling owners of suspect batteries that the batteries test OK, send them home, and the problem is finally resolved with a new battery. I have seen this mentioned over and over.
In my case, everything tested fine, but even after a week of daily overnight charging (at 13.5 volts) my battery is still losing charge. I did not like hearing from the dealer that they would need my car for at least 2 days to try and diagnose the problem.

[Glen e]

Originally Posted by 17rsvert

It doesn't matter how high tech the test equipment is if the techs can't get to the root cause of the problem. Dealers keep telling owners of suspect batteries that the batteries test OK, send them home, and the problem is finally resolved with a new battery. I have seen this mentioned over and over.
In my case, everything tested fine, but even after a week of daily overnight charging (at 13.5 volts) my battery is still losing charge. I did not like hearing from the dealer that they would need my car for at least 2 days to try and diagnose the problem.

I was one the first ones here in 2016 to report on this problem. As far as I’m concerned it’s never been figured out. Now I have a battery disconnect switch that I engage for longer than three days, and I carry a jump pack. I’m tired of trying to figure it out It’s been to two different dealers and both of them tell me no fault found.

[TedJS]

Originally Posted by 17rsvert

It doesn't matter how high tech the test equipment is if the techs can't get to the root cause of the problem. Dealers keep telling owners of suspect batteries that the batteries test OK, send them home, and the problem is finally resolved with a new battery. I have seen this mentioned over and over.
In my case, everything tested fine, but even after a week of daily overnight charging (at 13.5 volts) my battery is still losing charge. I did not like hearing from the dealer that they would need my car for at least 2 days to try and diagnose the problem.

True but... For the GR8 to properly test the battery you have to disconnect it from the vehicle. Given the challenge to access the battery on that vehicle most technicians are probably not doing that.

You might be better off removing the trim pieces prior to bringing the vehicle in so the technician would be more likely to properly test the battery. GM doesn't pay the technician if they don't find a problem and diagnostic time is a challenge to get under warranty for most techs so... Nature of the beast.