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!

[Grit_dog]

Way to go bud!!

[jornvango]

Update: replaced the car battery and, even on mornings when it's teens outside, the car starts fine.

[dodge_guy]

You have a bad battery. Those testers the parts stores use always say good battery. The batteries from the chain parts stores are cheap and will only last maybe 3 years. The fact you are getting 14.7 running shows the alternator is working. The battery has a bad cell.
Get a new quality replacement battery. I use AGM's and get 9 years out of one.

If you by cheap you get cheap!

[SweetLou]

jornvango wrote:
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!

Charge the battery well. Then do a load test. If it passes, you go on from there. If not, change battery and continue on sir

[Grit_dog]

blofgren wrote:

Grit dog wrote:

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.

Reminds me of your alternator story with your Tahoe! :B

Lol!
Kinda wishing I hadn’t sold that thing now!

[Groover]

I had a really weird situation a few years ago with a Sable that would pull the battery down overnight. It seemed to have an excessive draw with the engine off. After trying several several things myself and a couple of mechanics I took it to the dealer and he put in a new battery, that was all. That didn't sound right to me but it did fix the problem. I did have the presence of mind to ask for the battery that the dealer had taken out and ended up putting it in my F250 with a motor 2 and half times as big. It worked fine in the F250 for several years.

I am still puzzled as to why that battery did the job in vehicle but not another one that should have been easier for it.

[jornvango]

rjstractor wrote:

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

Question- did they remove the battery and do a full load test? Just checking the static voltage in the car right after driving it only tells you that the battery has a surface charge and that the alternator works. A specific gravity test (hydrometer) was suggested but that's a little tough (impossible) to do on a sealed battery. I'm with the others, the battery is almost four years old and is toast.

Thanks. No, what they do is attach their testing tool while the battery is in its regular place. While monitoring the past few days in mild overnight temps, the car starts fine. For example, the past 2 days, we didn't drive the car and it started fine. Battery was at 11.9V before we started it, which probably means there's nothing drawing it very low while we're not using the car. Which also probably means that it's a battery problem then as many have suggested ... time to replace.

[blofgren]

Grit dog wrote:

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.

Reminds me of your alternator story with your Tahoe! :B

[wopachop]

Still under autozone warranty? If the battery dies on you but still passes their load test you have to purposely kill the battery worse. Turn on 12v incandescent lights and run it down super low. If it still passes their load test talk to the manager. They have to power to call the battery bad.

Same thing happens to us during our mild winters. Truck wont start in the morning but the battery tests ok at autozone.

[rjstractor]

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

Question- did they remove the battery and do a full load test? Just checking the static voltage in the car right after driving it only tells you that the battery has a surface charge and that the alternator works. A specific gravity test (hydrometer) was suggested but that's a little tough (impossible) to do on a sealed battery. I'm with the others, the battery is almost four years old and is toast.

[Groover]

If you are not ready yet to change the battery you might want to run a few more tests. Keep in mind that what really matters is the voltage to the starter. Connect your positive voltmeter lead directly to the starter and your negative lead to the block and see what voltage the starter is getting. If it is more than a volt or so lower than what you have been finding at the battery you may have a problem with the wiring.

Check battery + terminal to starter during starting to find the drop in that wire and engine block to battery negative terminal to find the voltage drop there. The return circuit is often overlooked but more critical than the hot side. A failure in the return circuit can cause seemingly unrelated problems elsewhere, like axle bearings. A bad ground strap from the engine to the battery can lead the return current to find an alternate path and the wheel bearings is one of them. Try to check the voltage drop across any connections or relays.

I tend to agree with the opinions that you most likely need a new battery but these tests are pretty quick and cheap so you may want to do them anyway.

[Dick_B]

Similar problem. I had the dealer change the battery under Delco warranty. The old one was a little over a year old. The dealer said they have found bad batteries in cars just off the truck from the factory. Either the batteries are not as good as they used to be OR the newer cars have parasitic draws that drain the battery even when turned off.
I'd get the battery replaced asap.
I bought a battery jumper. Cheap insurance against being stranded.

[midnightsadie]

swap batteries from another car. just for a test.

[bikendan]

w2dart wrote:
Do a Battery Load Test

AND a hydrometer test.