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2009 G5 - Dead Battery - TWICE


I have a problem with my daughter’s new 2009 Pontiac G5. For the 2nd time in 4-months the car wouldn’t start because of a dead battery.

The 1st time the Pontiac dealer just said something was left on & drained the battery. They charged it and said there was nothing wrong. I let that go as a fluke since its supposed to have run-down protection to shut off whatever may be left on.

Well, it happened again. This time they charged it and let it set all weekend & said the discharge was in normal limits & started fine. They were a little less than pleased when I insisted on getting the number for Pontiac Customer Service. I haven’t called them yet but am planning on it.

I will add that my daughter only drives about 1.5 miles each way to work. She seldom drives much further than that. The last time the battery was dead the car had been setting for about 2.5 days. The good folks at the dealer said she wasn’t driving the car far enough to keep the battery charged.

I’ll buy that to a point but this is a brand new car & should be in top condition. She previously had a 2002 Cavilear(purchased new) and never had a problem with the battery not charging when driving short distances.

Are the mechanics/dealer just too lazy or dense to properly diagnose this or is the charging system weak in this car? I want this resolved so she won’t get stranded somewhere. She has On-Star which doesn’t do any good if the battery is dead. HELP !!!

Even new batteries are sometimes bad. I assume that the alternator has been tested and is putting out at least 14 volts and that the battery has been load tested?

I have no idea what procedures they’ve used in the diagnosis of this car and assuminmg any voltage drain is within the normal limits as claimed, is it known if they actually tested the battery itself?

The problem is not likely an issue of driving the car enough and could be the battery itself. New or nearly new batteries fail all of the time so the battery should be charged and then load tested.

Since this car is an '09 odds are it has a production date from late '08? This means the battery was produced some months before the production date and the battery could well be a year or more old, depending.
Sitting on a car lot awaiting a sale is not good on any battery either. (referred to as sulfating) Most batteries hold up well but a number will not.

Over the last 5 or 6 years I’ve had several car batteries fail within a year and this past summer a new battery for my lawn tractor went belly up within a week.

The paperwork shows 11.88 volts and cold crank amps of 449. The draw down test over the weekend was .003 MA which was all in acceptable specs, acording to them anyway.

“I will add that my daughter only drives about 1.5 miles each way to work. She seldom drives much further than that. The last time the battery was dead the car had been setting for about 2.5 days. The good folks at the dealer said she wasn’t driving the car far enough to keep the battery charged.”

I have to say that I agree with the dealer’s mechanics.
A car that is typically started and only driven for 1.5 miles is going to develop a whole litany of mechanical problems over the long term, and is likely to wind up with a dead battery in the short term.

This car needs to be driven for AT LEAST 45 minutes once each week in order to prevent severe sludging of the oil, premature rotting of the exhaust system, and dead batteries.

We change the oil more often becaus of the short trips. If the exaust rots, well it’s going to rot. She previously had a Cavilear and had the same driving habits and not aingle issue with it.

They only showed it as putting out 11.88 volts which sounds a bit low to me (also pointed out by a previous poster). I think it should have been closer to 14 volts to be “normal”. Every car I have ever had that actually showed volts always ran around 14-15 and never had a battery or alternator issue. I normally didn’t replace a battery until it was at it’s end-of-life of 60+ months.

I’m going to talk to a different dealer today and see if they will verify the output of the alternator and also that the battery is ok. I’ve had issues with the dealer that checked it as being less than truhful about their service.

I don’t exactly disagree with VDC but I would not go that far. I would recommend at full temp drive (45 minutes is good) one a month is a good idea. I would also note that oil changes are generally recommended on miles or months which ever comes first. See that you stick with that one.

I am not at all sure that the battery problem is being caused by the short drives, but it is possible.

The paperwork shows 11.88 volts Assuming this was measured with the engine running, then it is low. I would want 13.5 - 14V. That number you posted is about right for an older/marginal battery. If it was measured with the engine on, then that would be an indication of a bad charging system.

It would be wise to remember that the rubber parts like tyres, belts etc, tend to age based on time as well as use, so even if they look OK tyres do have a limited life on the shelf or sitting in the garage.

She probably does 1 maybe 2 trips a month of 45-60 minutes each way. Right now it has about 800 miles on it. The 2002 Cavilear she had for about 7 years had only about 12k on it when it was passed to her younger brother. Maybe 2-3k of that was from taking it on vacations.

Just a few other notes: She normally drives during the day so the only real extra draw is the driving lights. She doesn’t like to use the AC either. So I’m thinking it’s not discharging while sitting at a traffic light. She does listen to her stereo which she has cranked up pretty loud. It has the optional sound system but I don’t know how big the amp is. I do know she doesn’t listen to it with the engine off.

The dealer said the battery voltage was checked at 11.88 volts with the engine off. Shouldn’t thatbe a bit higher?

Yes, the 11.88 volts is too low, depending.
The voltage could be that low if the battery is run down a bit. A good battery, after being on a charger for at least an hour, should show around 12.6 volts.
If it does not, the battery is bad.

Since I assume the people you’re talking to are the service writers you should keep in mind that very, very few of these people have much mechanical aptitude and it’s possible they could really think that 11.88 is fine.

I have to question if they’ve tested or even considered the battery being the problem if they provided this 11 volts information without charging the battery first.

I should have added that a 12 volt battery consists of 6 cells; each of which provides 2.1 volts for a total of 12.6. (assuming a good battery)

If the battery has removeable caps it’s very easy to test the individual cells with a voltmeter and determine if one of those 6 is weak; meaning a bad battery of course.

A fully charged battery should read about 12.6 volts with the engine off. I use the following to determine the charge on a battery.
Battery Voltage Approximate Charge
12.65 V - 100%
12.45 V - 75%
12.24 V - 50%
12.06 V - 25%
11.89 V - 0%

This table indicates your battery is completely discharged. When the battery voltage of my 2000 Blazer was down to 12.1 volts, it started having driveability problems. I use a 4/1 amp battery charger and a Battery Tender ( to keep the batteries in the Blazer and a 93 Caprice (only driven once or twice a week) fully charged. The Battery Tender can be left connected to the battery pretty much indefinitely without fear of overcharging.

Has your daughter ever considered walking or riding a bike to work (only if it’s safe of course)?

Ed B.

That you’re saying makes sense. What the dealer put on the order was the voltage after it was fully charged by them (11.88). I called a second Pontiac dealer and he also said it was within “specs” but would check it. He wouldn’t say what the specs. were, just that it was in it. To me that still seems really low for a fully charged battery in almost brand new condition.

Thanks for the thought but walking or taking a bike really isnt an option here. It’s a pretty busy area especially during the day, 4-lane busy city traffic & no good way around it either by foot or bike. The weather in NW Ohio isn’t always the greatest either but it’s home.

The only thing I can think of that that all of those people are clueless or there is a huge disconnect between the mechanic who checked the car and the person you talked to, the service writer. The latter is very common.

Fully charging the battery and getting only 11.88 volts means the battery is hovering near junk status.
No way is 11+ volts a “normal” battery. Contact the GM regional office and drag them into this right now.

From what I can make about this problem it sounds to me that the alternator isn’t doing its job for some reason. The voltage at the battery should be around 14.8 volts while the engine is running around 2,500 RPM. If you aren’t getting at least 13.5 volts at the battery with a good load on the system then the alternator needs to be checked and most likely replaced. I would like to see what the results were of the alternator test and not just the battery capacity.

As far as the daily driving that she does on the car I would think it should be ok to keep the battery level up as long as the alternator is ok along with the wiring. I may be wrong about that but that is what I think at least.

I suspect that the 11.88 volts was at the end of the load test and the results indicate 449 CCA. Certainly the dealer can load test a battery. They have more sophisticated testers that allow them to test discharged and less than fully-charged batteries as well. I think that the other test result was more likely 3 mA or 0.003 A as well. There is a communication gap here.

The way I was taught to do a load test was to apply a load of one half the CCA rating of the battery. After 15 seconds, if the voltage was higher than 9.6 V, the battery is good.

There is something funny going on as far as communications. I haven’t been able to talk to the tech that did the test, just the service writer.

I’m going to take it to a place called the Battery Wholesale Warehouse and get a test there. If they show it’s bad, I can either take it to the Pontiac Dealer and argue that it’s really bad or put in a new battery with more reserve capacity than the current unit.

It may be a day or two before I can it in there but will post back with what we come up with.

With todays shops it is hard to talk with the person that did the actual work. Keep us posted using this same thread.