e6bailey

I just got an 2002 Coupe with 20,000 miles on it. It has been sitting in the garage for about 3 weeks due to the weather. I have tried to start it and drive it a few times and the battery is always dead. Once I get it running and drive it the battery will last for about a day and then it will be dead again. I replaced the battery thing it was that and it is still doing it.

Anyone one have an idea on what could be draining the battery like this.

I wasn’t really bothered by it because I figures I would take it to the dealer since I paid $2000 extra for the GM Major guard Warranty. Come to find out in the fine print which I thought I read there is a $100 deductable that I did not know about. Kind of pissed about the deductable but I guess you shouldn’t trust the F and I guy when he tells you there is not one.

Bob Chapman

Have a reputable battery person check your battery. If you let your car sit for over 2 weeks without a charger on the battery the on board computers will discharge the battery.

brucemoose2

Huh? I think you'll find that this is not true for everyone. If it's true for you, you may have a weak battery.

Regarding the original question, I'd be suspicious of your "new" battery. Check voltage while cranking to determine if there could be a bad cell or some other issue with it. It might show good voltage without load on it, but significantly lower voltage while cranking.

dieseldave56

Read your owners manual that clearly states that if your car sits idle for 3 weeks or more put a battery tender on it. But all the batteries in the world will not help if you have an excess drain . How long did you drive the car once you had it started ? If the alt is not putting out there's a possibility, ya think? What does your DIC say.

vettenuts

If this is the original AC Delco AGM battery that came with the car, replace it. When mine went, it was literally with a "BANG" and I was afraid that the electrical system might have been damaged. Fortunately, it wasn't. The original AGM battery will also strand you without warning. The Exide Orbital I installed has been excellent and much better than the original GM battery that came with the car.

There are a lot of horror stories about guys getting stranded with the original AGM battery.

stonecoldsaysto

Even though Batt terminals seem tight-- TRY to wiggle them to see if they really are as some terminal screws are too LONG & Will NOT GO IN FAR ENOUGH _ SO YOU MAY Have to add a Washer !!! At Least check !!!

BLOWNBLUEZ06

Start car and look at your voltage on the dash. Turn on headlights and heater or A/C on high and see where your voltage is at. Use a volt meter to measure at the back of the alternator and across the battery terminals. If they are all above 13 volts with all of the accessories turned on, your charging system is working. Turn the car off and monitor the battery voltage over a few hours. It should settle down to about 12.6 volts. If it creeps much lower than that within 24 hours, re-charge it and then disconnect it and check it again within 24 hours. If it is then keeping it's voltage, then you have something draining your battery. I have seen things such as trunk lights, glove box lights and under hood lights cause the drain.

Bill Curlee

THIS IS NOT TRUE! I have let my 02 ZO6 and my 98 Coupe sit (with out any chargers, jumps or battery assistance) for WELL over a MONTH and they both start and run just FINE! No problems what so ever. Do you think GM has all the C5 / C6's that they build on trickle chargers out in the BIG Bowling Green Storage lot where they store all the cars that they build??? I don't think so! There are times when some of those have cars have sat out there for weeks. They all have good batteries able to maintain the designed 20-30 milliamp current draw for at least a month maybe even TWO.

If you have a marginal or defective battery, NO, they will NOT hold a charge for any reasonable period of time. Even at the correct 20-30 milliamp current draw. If you leave the doors open and or play your stereo while you vacuum your car and after your done the car wont start, you need a new battery.

If you have a KNOWN good battery (tested to ensure that its good) and it still goes flat after it sit for short periods of time, you have an EXCESSIVE CURRENT DRAW issue! PERIOD!

There are hundreds of post (20-30 of them posted by me) on this very subject and what to do to monitor your BCM sleep current draw. Look up "ALL" post by Bill Curlee or,,,do an advanced search on battery current draw or current draw, and you will fine Lot's of post.

The correct method to determine a batteries condition is with a hydrometer and a load tester but, our batteries are SEALED and you don't have access to sample the electrolyte! So, all you can do is load test and voltage test it.

Take the battery OUT of the car, fully charge it. Once it is FULLY charged, take it to a reputable automotive store that knows how to properly test a battery and can use one of the new digital battery load tests and have the battery tested.

It should maintain a specific VOLTAGE, for a Specific period of time, under a specified CURRENT LOAD. If the battery passes that test and recovers to a satisfactory no load voltage , then it is GOOD and you need to investigate other causes for the battery draining issue.. If it fails any of the test, replace it.

Just because a battery is old, doesn't necessarily mean that it is bad or going bad. The battery in my 98 lasted 6 years. (yea,,,I rolled the dice on the leaky acid problem and won )
The battery in my 97 F-150 is the ORIGINAL OEM battery It still works FINE and oh,,,by the way,,, it also sits for weeks at a time without being used. Starts every time I ask it to. The wife made me purchase a new battery and have it in the garage just in case the old one fails, I want to see how long it will last!

If you have battery questions or problems let me know and I will try to help you out. There are many different ways to figure out what the battery is or is not doing. If you have a meter, it makes the testing really easy.

Bill Curlee

e6bailey

Thaks for the Feedack, I also agree that it should hold a charge for a long period of time that is why I think there is somethig draining the bat., I will just have to try and find out whats draining it.