Battery not charging fully

[RdHawg]

Our 16 Suburban has been struggling with electronic gremlins for a while which I’m now realizing are likely going back to a failure to properly charge. Had to replace a TCM, halogen headlamps, and a 2yo battery that was totally DOA at Costco.
I replaced the alternator and the battery and I’ve been checking the battery every few days and it seems the system never wants to charge the battery past 75-80% charge.
It’s a daily driver so even if it had a parasitic load it should be getting recharged every day.
I’d sure like to figure this out before I send another battery to the grave.
Suggestions?
Thanks.

 

[Joseph Garcia]

What are you using to determine that the battery is only charging to 75-80%?

 

[RdHawg]

What are you using to determine that the battery is only charging to 75-80%?

I have an Microprocessor controlled charger that gives me state of charge.

 

[LsHart]

Getting batteries from Costco? What's the type of battery and name? More than likely repops

 

[RdHawg]

Getting batteries from Costco? What's the type of battery and name? More than likely repops

Don’t know about everywhere but around here it seems Costco only sells interstate.

 

[LsHart]

Those are not repops. Are u charging the battery with the truck hooked up to the battery or just the battery?

 

[RdHawg]

Those are not repops. Are u charging the battery with the truck hooked up to the battery or just the battery?

I just leave the charger on and run it up to 100% while it’s still hooked up to the truck. According to chatGPT the truck might be operating normally or maybe needs its battery management system calibrated. I trust chatGPT about as much as a tabloid. Maybe someone here can comment on its suggestions and or recommend a decent bidirectional scanner to recalibrate the system ?

 

[Fless]

Lead acid or AGM battery?

 

[RdHawg]

Lead acid or AGM battery?

AGM

 

[LsHart]

Shouldn't have to keep a charger on a AGM battery. Maybe a maintainer at 1 or 1.5 amps. But not constantly charging. And only if it does more sitting than running.

 

[LsHart]

I would figure if that needs to be done every battery change then it would be easily fixed thru the dash controls. Than everyone that has that problem to have to take it to the dealer for that? I'm sure ur charger turns off when charged? Could fry some stuff

 

[Doubeleive]

as far as I know there is no calibration for the rvc on this generation, the vehicle charging system is not going to give you 100% state of charge

 

[RdHawg]

Tried to help a lady with her bmw battery once - turns out you have to be a dealer to train the car to its new battery- no thanks, I’ll drive an old beater first.
My charger does turn itself off so I’m not worried about frying anything that way. I’ve been checking the status about once a week, always 75-80%. Maybe I’m overly concerned? Replacing the battery is bad, replacing a fried undervoltaged TCM will make me utter bad words at loud volume.

 

[LsHart]

I do remember that on certain vehicles u have to plug in a "keep alive" adapter into the OBD connector to change the battery. For pcm memory

 

[Fless]

Tried to help a lady with her bmw battery once - turns out you have to be a dealer to train the car to its new battery- no thanks, I’ll drive an old beater first.
My charger does turn itself off so I’m not worried about frying anything that way. I’ve been checking the status about once a week, always 75-80%. Maybe I’m overly concerned? Replacing the battery is bad, replacing a fried undervoltaged TCM will make me utter bad words at loud volume.

Replacing the battery in the BMW would require registering the new battery with the vehicle. Easily done with a capable scanner. Registering it resets charging adaptations and possibly a few other data points within the vehicle's systems.

 

[GMCChevy]

Battery and charging issues shouldn't be causing those failures.
I haven't had many new batteries last more then a couple years. Was it only the one that was bad after 2 years? Maybe it was a dud. Charging wise rf you aren't having problems with your battery regularely going dead don't worry about it.

 

[RdHawg]

Battery and charging issues shouldn't be causing those failures.
I haven't had many new batteries last more then a couple years. Was it only the one that was bad after 2 years? Maybe it was a dud. Charging wise rf you aren't having problems with your battery regularely going dead don't worry about it.

We have arrived at a sad state of affairs if we can't expect more than a couple years from a "High Quality" battery. although based on the input from most on here I'm thinking I might be over-thinking.

Thanks everyone...