Charging system issues

[Parts Peddler]

So, I was driving home Friday night when suddenly my DIC displayed "Battery Saver Active". I turned my DIC to battery voltage and it read, 10.9 volts. After a couple of minutes the DIC read "Service Changing System". Fortunately, I was able to make it home, about 15 minute drive. I put my charger on the battery and called it a night.

Saturday morning, I started my diagnosis and my Topdon battery and charging system tester showed no output from the alternator. Seemed like a slam dunk. I pulled the alternator out. Fortunately, it's an easy job. I took it O'Reilly's to have it tested. It tested good. I was not expecting that. Now I was puzzled.

So, I took it to Autozone to get a second opinion. Again, it tested good. Damn!

Next, I took my battery out and took it to Autozone to be tested. It was a Delco 94RAGM, about 3 1/2 years old. It tested low, 12.3v. That's when I noticed that one end of it was beginning to bulge a little. I took that as a sign that it was on its way out, so I bit the bullet and bought a new Autozone battery.

I came home and reinstalled the alternator and the battery. Started my car and voltage showed 12.0v. I drove around for a little over a half hour, then stopped at Autozone to have the system checked while in the car. While driving, the voltage dropped, slowly, to 11.5. At Autozone I was told the battery voltage was too low to test the charging system or the battery.

I drove home. Along the way, the voltage dropped to 11.3v. I came inside to ponder the situation.

Today, Sunday, the 16th, which just happen to be my birthday, I threw my charger on the battery in the morning and went out with the wife for a few hours. I came back to a Delco battery current sensor that I ordered sitting on the porch. Yay me! I installed it but my issue persisted.

I've run out of ideas. Could the alternator still be the problem, even though it tested good, off the car?

Does anyone have any other thoughts on what the problem could be? I'm baffled.

Thanks in advance for any and all suggestions.

[KillboyPowerhead]

Maybe a blown fuse? See attached; hope they help. Good luck!

[chevy pilot]

First disconnect - cable and put charger on the battery and let it be a night.
In the morning, measure the battery voltage without the - cable.Must be over 12.6V.
Connect - cable and measure the battery voltage.
Start the car and measure the charging voltage from battery.
Let it be 0.5-1h and measure the battery voltage again.

It would seem to me that something is draining the battery badly while it is connected

[1JEWLDSSRS]

Just a heads up from what I have learned on here, and other websites concerning "new" batteries. When you purchase a new battery from the store, they are usually NOT at full charge from sitting. The battery companies charge them when they are new at the factory and put them through their testing, which draws out a lot of voltage. When they pass, they are shipped with whatever voltage is left. So when you install it, there is usually enough to start your car, and the ALT will keep up with it, but these ALTs are NOT designed to be a battery "charger" as one would think, they charge a little, but not enough to fully charge the battery. It is suggested, as I searched, on a new battery you do a FULL charge on it before installing it. When I bought my NEW AGM battery, it took 8.5 hours with my CTEK 7000 charger to bring it up to full charge. My suggestion is to fully charge the battery overnight and see where you are then. Hope all this makes sense. Good luck!!

[Parts Peddler]

Originally Posted by 1JEWLDSSRS

Just a heads up from what I have learned on here, and other websites concerning "new" batteries. When you purchase a new battery from the store, they are usually NOT at full charge from sitting. The battery companies charge them when they are new at the factory and put them through their testing, which draws out a lot of voltage. When they pass, they are shipped with whatever voltage is left. So when you install it, there is usually enough to start your car, and the ALT will keep up with it, but these ALTs are NOT designed to be a battery "charger" as one would think, they charge a little, but not enough to fully charge the battery. It is suggested, as I searched, on a new battery you do a FULL charge on it before installing it. When I bought my NEW AGM battery, it took 8.5 hours with my CTEK 7000 charger to bring it up to full charge. My suggestion is to fully charge the battery overnight and see where you are then. Hope all this makes sense. Good luck!!

Thanks. I agree completely. I used to work in an auto parts warehouse that stocked 1000's of batteries, and sold about 500-1000 batteries a day. That's right, one thousand! 10-20 pallets a day. I'm aware of the stale battery.

That being said, I checked the battery before installation and it was at 12.81v.

[Parts Peddler]

Just to let everyone know. I got a cheap alternator from Amazon. I didn't want to pop for a high priced higher quality one, in case it didn't work. I didn't want to be stuck with it. I just finished installing it and it works like a charm! Apparently, an alternator can bench test good but not work on the car. Keep that in mind if you ever run into a similar situation.

Sent from my SM-S921U using Tapatalk

[1JEWLDSSRS]

Originally Posted by Parts Peddler

Just to let everyone know. I got a cheap alternator from Amazon. I didn't want to pop for a high priced higher quality one, in case it didn't work. I didn't want to be stuck with it. I just finished installing it and it works like a charm! Apparently, an alternator can bench test good but not work on the car. Keep that in mind if you ever run into a similar situation.

Sent from my SM-S921U using Tapatalk

Very cool! Glad that did the trick for you.. Thanks for letting us know.

[Parts Peddler]

Thank you to all who provided suggestions. And a big thank you to Killboy do the charging system files. I just wish I was smart enough to understand most of the information.

I have one more question. Now that I have a functioning alternator again, how long should it continue to charge at 15v? I've been driving for a couple of hours and it's been at 14.9-15.2 the entire time.

Sent from my SM-S921U using Tapatalk

[gtstorey]

Originally Posted by Parts Peddler

Thank you to all who provided suggestions. And a big thank you to Killboy do the charging system files. I just wish I was smart enough to understand most of the information.

I have one more question. Now that I have a functioning alternator again, how long should it continue to charge at 15v? I've been driving for a couple of hours and it's been at 14.9-15.2 the entire time.

Sent from my SM-S921U using Tapatalk

It sounds like you still have issues unless you have a lot of added on drain on the battery. Battery could be getting weak or the new alternator may not be up to the job.

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