# Bad Battery?



## JunkieXL (Nov 24, 2017)

I bought my 2017 Cruze LT Nov 2017. Since then and for the last 3 years now, when I at work (Mon-Sat) I sit in my car during my breaks (2x15min, 1x30min) listening to the radio etc, car only in Accessory, so I get radio and LED DLR's only etc.. Well tonight for the first time ever on my lunch break, I get a screen prompt "Low battery, please start car" ok weird. Started the car and scrolled to the battery voltage menu. Reads 11.8V and is charging rapidly with car now on. Takes about 1 min to get to 14.5V where it settled. I turned the car back off and 10 mins later I turned the key to ignition(?) where everything comes up but cars not actively starting and dash reads 11.9V. So in a span of 10 mins with car off, Battery depleted from 14.5V to 11.9? That doesn't seem right. Car still cranked fine, headlights were normal bright. 

Is this normal behavior, or something I need to be worried about? I've never gotten that prompt before and there are no CEL lights on dash etc. 

EDIT: I checked the leads with a voltmeter under the hood and on battery itself in the trunk after it sat for 1 hour after I got home, both spots read 12.26V


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## Thebigzeus (Dec 2, 2018)

I would take it to an auto parts store or Walmart and have it load tested. It takes about 30 minutes and is free cause they want it sell you a replacement.


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## JLL (Sep 12, 2017)

2X on the load test. Is you battery still under warranty with GM?


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## snowwy66 (Nov 5, 2017)

My 17 got a new battery 3 months in. But it sat for 13 months before I bought it new.


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## Eddy Cruze (Jan 10, 2014)

When I listen to my Radio in the Car I *never* turn on Accessory, I just press the Radio button? Why do you need special DRL lighting while listening, this is running down your battery


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## Snipesy (Dec 7, 2015)

JunkieXL said:


> So in a span of 10 mins with car off, Battery depleted from 14.5V to 11.9?


No. That’s not how it works. That’s just the charging voltage.

Under ideal open circuit scenarios 12.1V is 50% SOC and 12.6V is 100% SOC. More or less same thing for AGM and Flooded.

Key word ideal open circuit scenarios where all cells are healthy. Which the car is not. You can read higher or lower than that. This is why the BCM has a current clamp to try and estimate the true SOC.


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## JunkieXL (Nov 24, 2017)

Eddy Cruze said:


> When I listen to my Radio in the Car I *never* turn on Accessory, I just press the Radio button? Why do you need special DRL lighting while listening, this is running down your battery


I never said I needed it. I work 3rd so it's at night in a busy parking lot and the DRL's just add a touch to the aesthetics. Never had an issue before that, doing the same thing. DRL's are LED, LED shouldn't use much power at all.

Now sitting there with engine off and headlights on, yea that would be stupid.


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## JunkieXL (Nov 24, 2017)

JLL said:


> 2X on the load test. Is you battery still under warranty with GM?


Yes, I was still covered under the 36k bumper to bumper warranty. That's what I ended up doing. took it to a local Chevy dealer, they put a new one in. If the old one was bad they didn't tell me. They just put a new one in and sent me on my way.


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## snowwy66 (Nov 5, 2017)

Snipesy said:


> No. That’s not how it works. That’s just the charging voltage.
> 
> Under ideal open circuit scenarios 12.1V is 50% SOC and 12.6V is 100% SOC. More or less same thing for AGM and Flooded.
> 
> Key word ideal open circuit scenarios where all cells are healthy. Which the car is not. You can read higher or lower than that. This is why the BCM has a current clamp to try and estimate the true SOC.


12.15 is 25%.

12.0 is considered dead.

AGM is 12.8V.


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