Battery Keeps Dying Help!!

[360kid]

I have a 2007 Chevy Impala with bumper to bumper warranty. I have had into the Chevy garage 3 times for a dead battery. I'll tell you about the problem and then what the garage has done to fix it. See if you can solve this mystery!

The battery goes dead if the car goes 4 days of so with out driving it. If I drive it everyday, no issues. When I go on vacation or a long weekend and let the car sit, the battery goes dead. So, I assume either:
1. Bad battery
2. Bad alternator
3. There's a drain on the battery.

The first time I took it to the Chevy dealership, they recharged the battery, tested the alternator and said everything is fine.

Still happens...

The second time I took it to the Chevy dealership, they said the battery was bad and installed a new battery.

Still happens...

Today, they had the car for 4 hours. The battery (new) tests fine, the alternator tests fine, and there is no parasitic draw on the battery. They are clueless! They do acknowledge the problem because they noticed the battery was almost dead after I just drove the car 45 minutes to get it to the shop.

I think the alternator is bad even though it tests fine. Is this possible? The dealership refuses to pay for a new alternator unless it actually shows up bad on the tests. I think it's the alternator because after driving the car 45 minutes to the dealership, the battery should be fully charged and it wasn't. It was almost dead. The battery certainly didn't lose over half its charge sitting in the parking lot for 5 minutes waiting for the mechanic.

Any ideas??

 

[motorguy222]

I dont know about this model and year but Chevy did have problems with the wiring harness that goes to the starter.If this is one of the cars that has problems it is because of the way that Chevy has set up the wiring.

The ones that have problems are set up so that the flow of current goes through the wiring harness that connects to the starter.The alternator charges like it is supposed to but because the harness is messed up,it does not actually charge the battery.

The alt. light does not come on or anything else because the alt. is actually charging.

The harness that could be causing this is the one that connects to the starter.It has 3-4 wires and they have fusible links in them.The wire and or link goes bad and that causes the problem.

Replacing the harness fixes this problem on the cars effected.

 

[chad8]

someone is missing either a bad ground or not testing amp draw properly for a drain on the battery. They need to pull fuses one at a time and see which circuit is grounded or not shutting off.
Sometimes it can be the alternator (regulator) itself.
In this case , I doubt it. A mechanic ,especially in a warranty situation , does not get paid enough to spend hours chasing down a current drain so they dump the problem on the next guy.
If you knew how flat rate and warranty work is paid , you would understand it better yourself.
Find another chevy dealership with an electrical specialist (special certifications from g.m.) , who will have more experience chasing down this kind of problem.
You have to ask the service department if they have the right guy on their staff.
Otherwise you get left in the situation you are in.
Do not let them tell you that all our guys are qualified.
That is a flat out lie.
Having a good friend in the business for 25 years , you learn a lot of inside secrets.

 

[JHZR2]

So there was an ammeter put in series with the battery cable to verify draw?

Are we sure all relays engage? Do we see 12v at the battery when it is "dead"?

Define dead in terms of battery voltage.

 

[360kid]

I had the first appointment at 8am this morning. It was a 45 minute (75mph) highway drive to the garage. They took the car right in, within 5 minutes they came and said that the battery is very low and would need to charge it for at least 45 minutes before they could begin any diagnostics.

After 3 1/2 hours, they came out and said the battery (2 month old) is fine, the alternator still tests fine, and the parasitic draw test came back normal (fine). They are stumped!!

They now want me to leave the car with them for at least a week so they can monitor it, un-driven, as the battery slowly dies (usually takes 4 - 6 days for it to die on me). I asked them what they would learn watching it die and they said they might be able to see what actually happens to the battery's power.

Again, even if there is a drain, if the alternator was fully functional, shouldn't the battery be pretty full after driving it for 45 minutes and I have been driving the car daily since I got back from my vacation and had to jump it? My gut still thinks it's the alternator.

 

[360kid]

Originally Posted By: JHZR2
So there was an ammeter put in series with the battery cable to verify draw?

Are we sure all relays engage? Do we see 12v at the battery when it is "dead"?

Define dead in terms of battery voltage.


I don't know "dead" in terms of volts. But... If it drive the car daily, it starts every time, no problem. If I let it sit 4 days the battery is too low to start the car, but the dome light and dash still work. If I let the car sit 7 days, not even the dome light or dash lights come on. It's very dead.

This morning, they said the battery was very low. I'm not sure how low it was, but the car started okay this morning and seemed fine like always.

 

[motorguy222]

Have the harness at the starter checked.It may be fine but it may be the cause of your battery problem.

If it is the harness to the starter,it is not a ground,it is a positive connection that is bad.

The current flow goes to the starter and then to the rest of the car.The harness in some Chevy cars has problems and causes the battery to not get charged.

You have the large positive battery cable and then you have 3-4 smaller red wires that are connected to the starter.One of the smaller wires is the cause of the problem if this is one of the effected cars.

If this is one of the cars,the harness will have to be replaced to fix it.

If a dealer/mechanic does not want to help,you can try the fix yourself.Get a used harness at a junk yard and see if that fixes your problem.Try to get a newer harness than the year of your car so that you can try to avoid the same problem.

The hardest part is getting to the starter on some cars.

 

[360kid]

Originally Posted By: motorguy222
Have the harness at the starter checked.It may be fine but it may be the cause of your battery problem.

If it is the harness to the starter,it is not a ground,it is a positive connection that is bad.

The current flow goes to the starter and then to the rest of the car.The harness in some Chevy cars has problems and causes the battery to not get charged.

You have the large positive battery cable and then you have 3-4 smaller red wires that are connected to the starter.One of the smaller wires is the cause of the problem if this is one of the effected cars.

If this is one of the cars,the harness will have to be replaced to fix it.

If a dealer/mechanic does not want to help,you can try the fix yourself.Get a used harness at a junk yard and see if that fixes your problem.Try to get a newer harness than the year of your car so that you can try to avoid the same problem.

The hardest part is getting to the starter on some cars.


Do you know if there is a service bulletin for this issue that I could take to the service department?

 

[JHZR2]

Originally Posted By: 360kid
Originally Posted By: JHZR2
So there was an ammeter put in series with the battery cable to verify draw?

Are we sure all relays engage? Do we see 12v at the battery when it is "dead"?

Define dead in terms of battery voltage.


I don't know "dead" in terms of volts. But... If it drive the car daily, it starts every time, no problem. If I let it sit 4 days the battery is too low to start the car, but the dome light and dash still work. If I let the car sit 7 days, not even the dome light or dash lights come on. It's very dead.

This morning, they said the battery was very low. I'm not sure how low it was, but the car started okay this morning and seemed fine like always.


Without voltages you cannot have an intelligent discussion.

An alternator is designed to top off the battery, not charge it. Have you tried to put it on a charger and let it really top off?

Need those readings, both at the battery and at the cig lighter, on and off.

After deep cycling more than a few times, the battery is shot anyway.

 

[360kid]

I borrowed my father in-law's multi-meter and got some numbers for you. Now, keep in mind that the battery was just fully recharged by the Chevy service center this morning.

Battery with ignition off about 12.5v (analogue meter).

Battery with engine at idle about 14.6ish volts.

Battery with a load (a/c on, rear defrost on, headlights, stereo, wipers all on at the same time) maintains about 12.8ish volts at idle.

 

[Carbon]

I am skeptical about there being no "parasitic load". With everything off, loosen the negative battery cable. You may need to wait until the interior lights go off. Get a multimeter, and set in the 1000 ma setting (at least 500 ma anyway). Hold one probe to the chassis. Hold one probe to the negative battery terminal. If the current draw is much over 80 ma, you have a load that you should not have. If you have 400 ma draw, that could explain your symptoms.

If you read 0 ma, you have a bad connection on one of your probes, your probes are not plugged into the right place, the fuse on the meter is blown, you are in the wrong range, or the meter has some other problem.

 

[Astro14]

Originally Posted By: Carbon
I am skeptical about there being no "parasitic load". With everything off, loosen the negative battery cable. You may need to wait until the interior lights go off. Get a multimeter, and set in the 1000 ma setting (at least 500 ma anyway). Hold one probe to the chassis. Hold one probe to the negative battery terminal. If the current draw is much over 80 ma, you have a load that you should not have. If you have 400 ma draw, that could explain your symptoms.

If you read 0 ma, you have a bad connection on one of your probes, your probes are not plugged into the right place, the fuse on the meter is blown, you are in the wrong range, or the meter has some other problem.


+1

 

[chad8]

just like I said +2

 

[doitmyself]

Originally Posted By: JHZR2
Are we sure all relays engage? Do we see 12v at the battery when it is "dead"?


I had a John Deere tractor with similar symptoms as the OP. Everything seemed to test out fine, yet the battery kep't dying.

After lots of trouble shooting, I found a bad relay (somewhere) in the circuit that was the problem. Like the OP, the symptoms made me think it was the alternator/voltage regulator.

Good luck and let us know the outcome.

 

[360kid]

Originally Posted By: Carbon
I am skeptical about there being no "parasitic load". With everything off, loosen the negative battery cable. You may need to wait until the interior lights go off. Get a multimeter, and set in the 1000 ma setting (at least 500 ma anyway). Hold one probe to the chassis. Hold one probe to the negative battery terminal. If the current draw is much over 80 ma, you have a load that you should not have. If you have 400 ma draw, that could explain your symptoms.

If you read 0 ma, you have a bad connection on one of your probes, your probes are not plugged into the right place, the fuse on the meter is blown, you are in the wrong range, or the meter has some other problem.


Well, if the battery is fine, new, the alternator is putting out enough volts, then there must be a parasitic draw on the battery. I will check that next. The Chevy garage said that there was no abnormal draw on the battery when they tested it this morning. I'll check myself anyways.

Thanks.

 

[Stu_Rock]

I am skeptical that parasitic drain is the entire problem. If the battery wasn't charged after a 45 minute drive, I don't think the charging system is working correctly. I looked at a diagram and it looks like the charging system in this car makes the following circuit:

Charge terminal post on alternator
Alternator cable bundled in engine wire harness
Terminal post at power distribution block
Battery positive cable (ignore *fat branch to starter)
*Battery positive terminal
*Battery
*Battery negative terminal
*Battery negative cable
*Ground/negative terminal on engine block
*Engine block
Alternator mounts/chassis
Alternator "guts"
(repeat list)

You could imagine electrons making round trips through that circuit in a bottom-up order the way I wrote it. Somewhere in that circuit, a component or connection is bad. It sounds like the car starts just fine, so let's rule out the sections that are shared with the starting system. I marked them with asterisks.

If the alternator checks out, the next thing I would do is measure the voltage between the alternator charge post and the battery positive terminal with the engine running. If it's more than a small fraction of a volt, the alternator cable is probably toast.

If that passes the test, measure the voltage between the alternator chassis and the negative battery terminal; engine still running. It also should be a small fraction of a volt.

Good luck.

 

[Warstud]

I think your alternator could be bad and is only working part-time. When the dealer tested it....it probably worked fine.

 

[motorguy222]

Originally Posted By: 360kid
Originally Posted By: motorguy222
Have the harness at the starter checked.It may be fine but it may be the cause of your battery problem.

If it is the harness to the starter,it is not a ground,it is a positive connection that is bad.

The current flow goes to the starter and then to the rest of the car.The harness in some Chevy cars has problems and causes the battery to not get charged.

You have the large positive battery cable and then you have 3-4 smaller red wires that are connected to the starter.One of the smaller wires is the cause of the problem if this is one of the effected cars.

If this is one of the cars,the harness will have to be replaced to fix it.

If a dealer/mechanic does not want to help,you can try the fix yourself.Get a used harness at a junk yard and see if that fixes your problem.Try to get a newer harness than the year of your car so that you can try to avoid the same problem.

The hardest part is getting to the starter on some cars.


Do you know if there is a service bulletin for this issue that I could take to the service department?


I dont know if a bulletin came out or not.I am not sure what years were effected either.I dont think it was actually ever really acknowledged.It may be one of those things that actually happens but the company does not 'know' about it.

 

[hooligan24]

this subject(electrical) is way over my head, and im not sure if this would even pertain to the problem. My car, a Dodge, the ecu decides how much power is givin to the battery from the alternator depending on loads/ambiant temps....etc. I have read numerous times on dodge forums where alternators and batteries have checked out just fine, but batteries keep dieing without excessive parasitic draw. Turns out they find a short or bad connection at the ECU. Might be something to look into if your vehicle uses the same design.

 

[JHZR2]

Originally Posted By: 360kid
I borrowed my father in-law's multi-meter and got some numbers for you. Now, keep in mind that the battery was just fully recharged by the Chevy service center this morning.

Battery with ignition off about 12.5v (analogue meter).

Battery with engine at idle about 14.6ish volts.

Battery with a load (a/c on, rear defrost on, headlights, stereo, wipers all on at the same time) maintains about 12.8ish volts at idle.


OK, 12.5V is not fully charged. Are we sure it was 12.7V at the terminals (after rest, it would likely sit at 13.x for a bit after charging) after they were done?

So, the next question is if there was an equalizing charge. Sounds to me like one cell is way weak but not shorted, so it will take a charge, keep it, put out some power, but the voltage will just drop like a rock as that one cell heads to reversal.

Next we need to know voltage per day, particularly if sitting, and voltage at failed start time.

The reading on the ammeter (put it in series between the positive terminal and the positive battery cable) will be helpful too.