Voltage gauge

[Mad Maxx]

I'll check Voltage at the Alternator tomorrow or Monday. I have the truck on my CTEK tonight to charge.

To me, the Voltage is Low, I've been in the Aftermarket Industry for over 15 Years, and 12v Electronics is one of my main fields.

But...on these "New Vehicles", you just don't know what's "Normal" anymore. I know if I take it to the Dealer, they'll tell me it's within spec and send me out the door.

 

[08grey]

It's normal. If your battery was taking a charge at 14.4 volts all day and night it wouldn't last as long as they do. If you want to test it plug in something with a high amp draw. If it's a 15 it should have a ac DC converter. Plug in a fan. Turn it on low then med then high. You should be able to see the voltage regulator kick in and start charging the battery.

 

[Mad Maxx]

It's normal. If your battery was taking a charge at 14.4 volts all day and night it wouldn't last as long as they do. If you want to test it plug in something with a high amp draw. If it's a 15 it should have a ac DC converter. Plug in a fan. Turn it on low then med then high. You should be able to see the voltage regulator kick in and start charging the battery.

I'll keep an eye on it the next few days. This could just be another thing to add to the list before I send it to GM telling them they NEED to buy this thing back from me and give me a New / Different one.

 

[wcourt]

OK, Here is the deal. I could not find anything on the low voltage/charging issue nor could the dealer provide any useful information so I requested information from GM. The following is their reply:

The Electrical Power Management Overview (as they call it) The electrical power management system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This electrical power management system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge and life, and minimize the system's impact on fuel economy.

Three functions are:

It monitors the battery voltage and estimates the battery condition.
It takes corrective actions by boosting idle speeds, and adjusting the regulated voltage.
It performs diagnostics and driver notification.

Charging system operation. The purpose of the charging system is to maintain the battery charge and vehicle loads. The engine control module (ECM) controls the generator output. The normal duty cycle is between 5 - 95%. The output of the generator is contingent on the on the duty cycle, e.g., 20% duty cycle yields 11.56 volts, 50% - 13.25 volts, 80% - 14.94 volts, etc.

The GM document is too long to post in this forum (please reference GM document ID: 2206057)

Bottom line is the lower volt meter charging is normal.

Good luck.

 

[angelmom05]

I know this is an old post, but I read the entire document you referred to here. My 2017 Chev Tahoe is doing the same thing. So I guess it’s normal?

 

[dbbd1]

I know this is an old post, but I read the entire document you referred to here. My 2017 Chev Tahoe is doing the same thing. So I guess it’s normal?

Yep!

 

[RED TAHOE LS]

Voltage gauge, $3.53 free shipping on ebay, plug in power/lighter. Had one for 3 yrs, perfect.
David g...........