Forgive me if this has been discussed to death. Shortly after buying my C5 it went to the detail shop. When I went to pick it up the battery was dead. Same thing when I had some updated audio installed. Then today, after a week in the garage, the battery was dead yet again. A quick charge remedied the situation, but is this normal? BTW, the battery is nearly new.

 

MY car can sit between week ends and start fine. I got all whipped up reading about the situation and started to put on a slow charge a day before running the car. I started to get column lock issues, so I quit that , and now the system is back, again stabilized.

No way to know what happened to the car outside of your control, but sounds like a current leak. The only other clue is the change to the radio. Sometimes people with extreme radios, or old cars, need to upgrade the alternator. I saw a lot of talk about fire engine alternators when I was researching a radio for another car. Perhaps you are drawing the battery down before you shut the car off.

I had some girls kill a giant battery , by playing the upgraded radio in an old jag, in about ten minutes, while I went into a convenience store. Big speaker magnets and a generator were the situation.

With an alternator this shouldn't happen , but outside of a circuit problem which I would try first, this would be the secondary suspect. I wouldn't mess with the alternator on this car, because of my skill level. I want those computers fed the same way , all the time.

MY battery in the used car also looked new, and a wet cell can take a lot of abuse. If you have another design , deep discharges can effect function.

Just trying to help. I know this is all real basic information and might not be needed.

 

No, not normal. You have a battery draw on your system. A proper diagnostic will let you know the remedy.

 

To see if your car has a current draw, disconnect the ground lead from the negative battery terminal and connect an ammeter between the cable and battery terminal and measure it. You also should fully charge up your battery and get it load tested. Most garages and battery places will do that for free. It could be nearly new, but bad, from multiple discharges. This could be due to something stupid, like the underhood light not going off when you close the hood, a trunk light on, something dumb like that.

 

Thanks all. I'll get it checked out ASAP.

 

If you need help with the parasitic drain test let us know. Once the car goes into "sleep" mode the drain should only be about 20 milliamps.

 

Same with mine and just bought the 2000...installed radio...strange huh.

 

The batteries in both cases could have been discharged very simply by the door or hood being open for a prolonged period of time with bulbs lit all day long.

 

I'm very fortunate to have a trustworthy and fair mechanic who I've done business with for years. It's going in for a diagnostic Monday. After not being driven for only two days this time it was dead this afternoon.

 

I'm going to jump in here since I've just discovered my 04 won't start so I installed a new battery and still NOTHING. It was parked in the garage and hadn't been driven for about three weeks. No previous trouble, it was running great and the old battery was three years 9 months old. I'm electrically ignorant so what's the next step, a rollback to the repair shop?

 

Thanks loads.

 

I MAY have gotten off easy. Time will tell, but my issue had gotten to the point lately my battery would drain overnight. Took the car to my trusted long time mechanic this morning for an electrical diagnosis, and apparently the culprit was a cell in the battery shorting itself. The battery showed a drain even when it was removed from the car. So a new battery, no diagnostic fee, and my heartfelt thanks to a truly honest mechanic.

 

Vette has been nestled under its cover in the garage since last Thursday. We arrived home from an out of state trip about an hour ago, and I hesitantly uncovered her for what I feared would be an electrical disappointment. Lo and behold, she started right up with what seems a very healthy battery. I guess I really did get off lucky (knocks on wood)

 

While doing research on C5's before i bought an 04,i decided to invest in a good battery tender (CTEK 3300).I then replaced the battery within a week with the biggest Diehard AGM that the tray would hold.The only time it is not on the tender is when i am driving or working on it.I know this will not prevent other issues but it should limit some of the electrical problems with these cars.