Battery problem

[jornvango]

2013 Chevy Tahoe with 120K miles. Battery was last replaced Jan '17.

For the past 8 months, especially after a cold night or when we haven't driven the car for a day or two, the car shows low battery level indicator and has trouble starting (but hasn't left us stranded ... yet).

A few months ago my wife left an interior light on which drained the battery enough so the car didn't start. We charged it by hooking up our solar panel to recharge it.

A few days ago after a very cold night (10 F), the battery was so low (as indicated by the gage on the dash) that it barely started.

Yesterday morning, after overnight temps around 35 F, again the battery level gage showed low and the car barely started.

We have been to Autozone / O'Reilly's multiple times and every time the battery, alternator and starter tested 'good'.

This morning I plugged a volt meter into the car. It again had trouble starting. Here are the readouts:

1. Before car start in the morning 12.0 V
2. During start 10.8 V
3. Started the car and during driving 14.7V
4. Stopped the car after driving 30 mins 12.5V
5. After 1 hour of not running 12.2 V

Any idea what is going on? It reallyfeels like one of these mornings the car is not going to start which will be a problem if we're camping off grid.

Thanks!

[2112]

I recently worked on an Escalade with the same symptoms. It was caused by a poor crimp connection on the negative battery cable. Where the lead terminal clamp is crimped to the copper ground cable. It would have been impossible to find it without a voltmeter.

[time2roll]

You have your warnings and data to confirm the battery is shot.
Get a new battery already.

Don't be this guy:
Battery exploded

[blofgren]

4x4ord wrote:
I think your battery is pooched.

Totally agree. Once they get run down once they never seem to fully recover.

My MIL's Mazda 3 had a similar problem and I was reluctant to think it was the battery because my BIL had recently replaced it. After coming up with nothing else, it was replaced with a OEM unit and the car has been fine since.

[w2dart]

Do a Battery Load Test

[Super_Dave]

I think that he wants to get stranded. Get a new battery and report back if it still has a problem.

[Grit_dog]

jornvango wrote:

Krusty wrote:
You should get a battery charger and charge the battery up fully. Also, if the battery and charging system test good, perhaps there is something drawing the battery down overnight.

We ended up driving a few hours today. Upon arrival at our campsite, the battery showed 12.2 and a few seconds later 12.0

Is there any way to test if there is a draw on the battery while the car is turned off?

This tells ya it's the battery. Even with a parasitic draw, the battery would be fully charged after a 3 hour drive. And if the alternator wasn't working, you wouldn't have made it to your destination.

[Seon]

Drive it to an O'Reilly, Autozone, Costco or a any Battery shop and have it load tested. It's a free test.

[PA12DRVR]

Slownsy wrote:
.The battery has had it
Frank.

This ^^^. Discharged to too low of level and won't hold adequate charge. Fairly regular occurrence (finding out about overdrawn batteries) in the first serious cold snap up here.

[ktosv]

jornvango wrote:
A few months ago my wife left an interior light on which drained the battery enough so the car didn't start. We charged it by hooking up our solar panel to recharge it.

My 2012 Yukon XL and 2017 Suburban both had/have battery rundown protection. If anything like a map light gets left on (like one of the kids leaving a light on on Saturday) after about 10 mins the truck shuts off what ever is on. Either your rundown protection isn’t working or you seem to have some other parasitic loss (as mentioned).

I am sort of thinking if the battery was drained for some reason and it was never properly fully charged after, the battery may be shot at this point. Your battery is also almost three years old at this point. They don’t make batteries like they used to, might just be time for a new one.

[theoldwizard1]

jornvango wrote:

4. Stopped the car after driving 30 mins 12.5V
5. After 1 hour of not running 12.2 V

Slownsy wrote:
.The battery has had it
Frank.

I think Frank may be correct.

The only other test requires a clamp on ammeter like a Uni-T UT210E - Amazon $50



After driving for 30 minutes and shutting the truck off, clamp the meter on either the positive or negative battery lead. It usually take 5-10 minutes for all computers to "go to sleep" so be patient. If the meter reads much more than 10-20mA you have a "parasitic load" pulling down your battery.

[CA_Traveler]

jornvango wrote:
Is there any way to test if there is a draw on the battery while the car is turned off?

A DC clampon meter will do the job, just takes a few seconds to display the draw or charge. Make sure to get one that measures DC amps. Most can display AC as well.

[4x4ord]

I think your battery is pooched.

[Turtle_n_Peeps]

Do an amp draw with a meter.

[Slownsy]

.The battery has had it
Frank.

[jornvango]

Krusty wrote:
You should get a battery charger and charge the battery up fully. Also, if the battery and charging system test good, perhaps there is something drawing the battery down overnight.

We ended up driving a few hours today. Upon arrival at our campsite, the battery showed 12.2 and a few seconds later 12.0

Is there any way to test if there is a draw on the battery while the car is turned off?