Charging issue on 2018 equinox 1.5 turbo

[ken68]

A week ago I needed a jump start I thought I accidentally left something on and didn't give it a second thought a few days ago I go to get gas shut it off and came back to leave and the battery was dead again tried a jump start and couldn't get it to start the battery is from 10/22 so the battery should be good so I thought I took the battery to be tested and it failed so I replaced the battery and noticed my battery voltage was low 12.2 volts it would occasionally go up to about 14 volts and fall off to 12.2 volts I thought maybe the alternator was bad and replaced it with a used one I'm.still experiencing the same issue I noticed that if I have my headlights on the voltage would go up and then slowly drop down to 12.4 volts again if I coast down a hill the voltage comes back up to around 14 volts and then accelerate and the voltage drops again the car has only 55k miles I don't have any warning lights i checked the mega fuses and the little 5 amp fuse by the battery all checks good so im.wondering if the current sensor is bad and that's my problem? I have a decent scan tool and nothing about the battery or charging system comes up I'm going to check the connections at the alternator to make sure I have the battery voltage and the signal from. The bcm so any ideas or inputs would be greatly appreciated or further information is needed let me know thank you

 

[CocoaJeff]

Welcome to the forum. Down here in the heat of Florida, a lifespan of 3 years on a car battery is pretty average. I don't think I've ever gotten much more than 3 or 4 years on any battery, even when I lived up north (winters can be very hard on them, as well).

 

[PoManNox]

Between the auto stop/start system, the smart charging system and the AGM battery itself, it's not uncommon for an AGM battery to go bad in 3yrs. I'm still rocking the factory battery in my 2021 @ 65K miles, but I know my days are numbered. Living in a climate that doesn't get hot helps.

What you are describing with the charging system voltage swings per the vehicle's dash is normal. The smart charging system drops the voltage disturbingly low at times at level, steady, cruising speeds as a fuel savings measure. Coasting downhill, it will boost it 14vdc or higher for some regenerative braking effort, or just plain why not.. we're coasting.

I would still run a load, charge and crank test on your battery with a good digital tester.

 

[ken68]

Welcome to the forum. Down here in the heat of Florida, a lifespan of 3 years on a car battery is pretty average. I don't think I've ever gotten much more than 3 or 4 years on any battery, even when I lived up north (winters can be very hard on them, as well).

Yeah it's a little different here up north in Pa the cold definitely effects the battery especially when it gets down to 10 to 20.below zero I find that interstate batteries are one of best ones out there they are very expensive but definitely worth the cost I've seen people getting 3 plus years from..them

 

[ken68]

Between the auto stop/start system, the smart charging system and the AGM battery itself, it's not uncommon for an AGM battery to go bad in 3yrs. I'm still rocking the factory battery in my 2021 @ 65K miles, but I know my days are numbered. Living in a climate that doesn't get hot helps.

What you are describing with the charging system voltage swings per the vehicle's dash is normal. The smart charging system drops the voltage disturbingly low at times at level, steady, cruising speeds as a fuel savings measure. Coasting downhill, it will boost it 14vdc or higher for some regenerative braking effort, or just plain why not.. we're coasting.

I would still run a load, charge and crank test on your battery with a good digital tester.

I did install a new battery so it's very possible that the original alternator is good but I'm.going to have it tested to verify it's in good condition and return the used one I'm.guessing by what you are saying is that the voltage swing from 12.4 up to almost 15 volts depending on the load is normal I'm so used to the older vehicles that maintain a steady charging voltage around 13.6 I do have a decent voltmeter to see where the voltage drops to during cranking and I'll stop by and have a load test done for peace of mind

 

[PoManNox]

I did install a new battery so it's very possible that the original alternator is good but I'm.going to have it tested to verify it's in good condition and return the used one I'm.guessing by what you are saying is that the voltage swing from 12.4 up to almost 15 volts depending on the load is normal I'm so used to the older vehicles that maintain a steady charging voltage around 13.6 I do have a decent voltmeter to see where the voltage drops to during cranking and I'll stop by and have a load test done for peace of mind

Yes, this smart charging system IMO is very hard on batteries. They seldom get to see full charging voltage. I don't know how to disable this system and not throw a code on GMs, but I do have it disabled on my daughter's 2022 Nissan Frontier. On the Nissan, it's a matter of de-pinning one pin on a 4-pin harness that plugs into the negative battery cable.

 

[57chevythunder]

-I agree with PoManNox. This "smart" charging system severely reduces the battery life.
The work-around that I use is this: Always run with the headlights on. This will keep the system well above the 12.4 volts which is the value when it is operating in the fuel economy mode.
A few years ago I did a pretty extensive study on lead acid batteries, automotive application in particular. A few things I learned:
-To prevent sulfation, our 12 volt automotive batteries must always be kept at or above 12.6 volts.
-Sulfation is the number one battery killer.
-Even at 12.4 volts, the battery is in sulfation mode. (I think somewhere around 10%?)

The only saving grace is that re-charging the battery will chemically convert most of the "soft lead sulfate" back into Lead and Sulfuric Acid. The sad fact is the conversion process is never 100% successful. And that which remains on the lead plates becomes "hard sulfate" which cannot be converted. So, with the slowly increasing accumulation of hard sulphate, the square inches of lead surface gets smaller and smaller, making the battery weaker. Consequently, a battery which had plenty of cold cranking current capacity for starting your car, eventually becomes too "small" to do the job.

My Equinox is a 2019, and the headlight mode works perfectly to keep the system voltage up where it needs to be to prevent sulfation. I would think yours should be the same.

Good Luck and lets us know how it works out.

BTW, the OEM battery in my Equinox is now over seven years old and still running strong. (And I will say it also helps that every time the car is home, it is plugged into a Battery Tender.)

 

[mjb]

I have a 2019 1.5 liter with 60k miles on it. Original battery and no special care. Daughter has the same car and original battery. Wife has a 2020 1.5 liter also with original battery. Borrowed time here I guess!

 

[PoManNox]

....My Equinox is a 2019, and the headlight mode works perfectly to keep the system voltage up where it needs to be to prevent sulfation. I would think yours should be the same.

Good Luck and lets us know how it works out.

BTW, the OEM battery in my Equinox is now over seven years old and still running strong. (And I will say it also helps that every time the car is home, it is plugged into a Battery Tender.)

Just curious.. Do you have the Bi-Xenon (HID) or halogen headlamps in your 2019?

 

[57chevythunder]

Gosh, I don't know. How do I find out?
It does project a bright white flat beam. And the high beam just moves that flat line a little higher, making the road reflectors visible a bit farther down the road.

 

[RIT333]

Sounds like you have projector headlights, which are probably not halogen. It probably looks like a big, clear marble, of maybe 3" diameter. The cut line is generated by a shade the covers the top part of the beam. It is helpful for not blinding approaching drivers, but is annoying on a hilly road, IMHO.

 

[57chevythunder]

"Sounds like you have projector headlights, which are probably not halogen. It probably looks like a big, clear marble, of maybe 3" diameter. The cut line is generated by a shade the covers the top part of the beam. It is helpful for not blinding approaching drivers, but is annoying on a hilly road, IMHO."

Thank you RIT333 for your reply.

Yup, you described them perfectly. And out here in Wyoming we have a lot of miles of hilly roads. I agree these lights are annoying in that situation. I also find that they don't shine enough light on the sides of the road, which is a real problem on nights when there are a lot of deer or other animals out.
Also, at an unlit intersection they sure don't light up anything very far left or right.
It takes a lot of getting used to.

 

[RIT333]

Yep, some engineer's great idea, wasn't great for all circumstances.