Time for a new battery. 
Dead Battery Mystery
Thread Starter
Heel & Toe
Joined: Apr 2011
Posts: 20
Likes: 0
Dead Battery Mystery
2005 C6 Convertible - last week I went to start it and the battery was totally dead. I had to pull the ripcord in the trunk just to get in the car. It had just been driven two days earlier and seemed fine then. I put it on the charger and it was accepting just under 6 A. After about 4 hours it had enough charge to start. The car's voltmeter was showing 14.2 volts. But now the windows weren't doing their little jog up when you close the doors. I also noticed the dash lights were staying on while it was charging.
So I took it to a local dealer who has a "World Class Certifed" Corvette mechanic. After keeping it overnight, he announced that the battery was OK, it just needed to be fully charged and that after a "thorough inspection" nothing else was wrong. He also "re-indexed" the windows.
I drove it home. Two days later (this afternoon), the battery is totally dead again. Any experts here have any ideas what might be wrong? Thanks!
So I took it to a local dealer who has a "World Class Certifed" Corvette mechanic. After keeping it overnight, he announced that the battery was OK, it just needed to be fully charged and that after a "thorough inspection" nothing else was wrong. He also "re-indexed" the windows.
I drove it home. Two days later (this afternoon), the battery is totally dead again. Any experts here have any ideas what might be wrong? Thanks!
Moderator emeritus
Joined: Jun 2001
Posts: 18,599
Likes: 3,954
From: Jacksonville Florida BWO Dayton, Cincinnati, Bloomsbury NJ, Cincinnati
2015 C7 of the Year Finalist
Car battery is not as good as the dealer thought. It won't hold the charge.
I'm voting for a replacement battery to get you fixed up.
Elmer
I'm voting for a replacement battery to get you fixed up.
Elmer
Team Owner
Joined: Oct 2004
Posts: 27,420
Likes: 64
From: San Clemente CA
You need a new battery. Don't fight it as these cars are very hard on batteries. Do a search and you find many question's just like yours. Almost always a new battery solves the problem. It did in my case. My original 2005 battery died in 22 months. I replaced it with an Optima RED top and over five years later it's still going strong. Good luck and keep us posted. 
Last edited by VET4LES; Aug 26, 2012 at 07:24 PM.
Thread Starter
Heel & Toe
Joined: Apr 2011
Posts: 20
Likes: 0
Thanks to everyone for the helpful replies. The battery was the first thing I suspected, but because the windows were behaving strangely, I decided to let the dealer look at it. I then figured that no self-respecting dealer would pass up the chance to sell me a new battery so if he said it was OK, it must be OK. Maybe not.
Good idea about the interior lights button, but that wasn't it. The mechanice said that it can happen if you don't shift into reverse when parking, but it dings loudly when you open the door in that case, so I didn't forget that.
At this point, the battery seems as likely as anything. In any case, I'm going to let the dealer handle it since he told me everything was fine and it isn't. They're closed now but I'll post an update on Monday. I'd hate to throw in a new battery myself and then find that one dead because there's something else wrong somewhere.
Good idea about the interior lights button, but that wasn't it. The mechanice said that it can happen if you don't shift into reverse when parking, but it dings loudly when you open the door in that case, so I didn't forget that.
At this point, the battery seems as likely as anything. In any case, I'm going to let the dealer handle it since he told me everything was fine and it isn't. They're closed now but I'll post an update on Monday. I'd hate to throw in a new battery myself and then find that one dead because there's something else wrong somewhere.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
New battery would be the first thing I would changes, if it wasn't the problem before, it will be a problem because every time you run it dead, you severely impact the life of the battery.
I don't know were you live, but I have over $3,000 of battery test equipment in my garage and will be glad to test you battery and charging system for you.
I don't know were you live, but I have over $3,000 of battery test equipment in my garage and will be glad to test you battery and charging system for you.
Moderator
Joined: Dec 2002
Posts: 40,898
Likes: 4,351
From: Lakewood Ranch, FL
Several things to consider.
1. You have a 2005 - it must be shutdown in reverse for the electronics to close out. You may have shut the car down in correctly, draining the battery. You should also check with the dealer - have the dealer run a report to see if the Body Control Module has been re-flashed with updated software. There is a TSB on this.
2. How old is the battery and how many times has it drained? Your description sounds like a bad cell in the battery. Cure is replace.
3. When power is removed from the car, one of the things that is lost is the window indexing - window indexing is when the windows lower slightly on opening and return to closed when the door closes. This is to relieve the internal air pressure and make door closing easier.
Cure is to re-index.
1. You have a 2005 - it must be shutdown in reverse for the electronics to close out. You may have shut the car down in correctly, draining the battery. You should also check with the dealer - have the dealer run a report to see if the Body Control Module has been re-flashed with updated software. There is a TSB on this.
2. How old is the battery and how many times has it drained? Your description sounds like a bad cell in the battery. Cure is replace.
3. When power is removed from the car, one of the things that is lost is the window indexing - window indexing is when the windows lower slightly on opening and return to closed when the door closes. This is to relieve the internal air pressure and make door closing easier.
Cure is to re-index.
Thread Starter
Heel & Toe
Joined: Apr 2011
Posts: 20
Likes: 0
First off, many thanks to johnodrake for the window re-indexing instructions. I had no idea this was something I could do myself. Next, I'm positive I did not forget to shift into reverse when parking. The car dings at you anyway when you open the door if it isn't in reverse. And thanks also to spartan 45 for telling me about the column lock bypass. I'm going to look into that too.
The more I think about it, the more it seems like it is must be the battery. What gets me though is that I've had bad batteries in the past and they always give some warning before they die, like slow cranking down to nothingness. This is the first time I've ever seen a battery go from hero to zero in one day that wasn't caused by some external drain. Thanks also to timd38 for the kind offer to check the battery, but I'm in NY which is a bit of a trip. Supposedly the dealer tested it anyway.
Now, I'll grant that it is the original battery and it did get drained once before, last year when it was stored for the winter and my float charger died. I'd just go ahead and put in a new one, but since I already took it to the dealer last week it's his problem now. We'll see what he has to say tomorrow.
The more I think about it, the more it seems like it is must be the battery. What gets me though is that I've had bad batteries in the past and they always give some warning before they die, like slow cranking down to nothingness. This is the first time I've ever seen a battery go from hero to zero in one day that wasn't caused by some external drain. Thanks also to timd38 for the kind offer to check the battery, but I'm in NY which is a bit of a trip. Supposedly the dealer tested it anyway.
Now, I'll grant that it is the original battery and it did get drained once before, last year when it was stored for the winter and my float charger died. I'd just go ahead and put in a new one, but since I already took it to the dealer last week it's his problem now. We'll see what he has to say tomorrow.
Moderator emeritus
Joined: Jun 2001
Posts: 18,599
Likes: 3,954
From: Jacksonville Florida BWO Dayton, Cincinnati, Bloomsbury NJ, Cincinnati
2015 C7 of the Year Finalist
When one of these batteries goes to 0, the internal plates can warp. When that happens they can short out cells. A shorted battery cell is like trying to swim with a great white in a kiddie pool. You're not going to like what happens. Get the battery, I doubt the dealer will give you a break on price. I have the red top Optima. Seems to be working nicely.
Elmer
Elmer
Thread Starter
Heel & Toe
Joined: Apr 2011
Posts: 20
Likes: 0
Thanks for the tip on the Optima battery. I read up on it and that sounds ideal for a 'vette that sits in the garage five months of the year. I'll ask for that when I talk to the dealer tomorrow. If he won't give me a decent price, then it's hasta la vista, ba-by :-)
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
When one of these batteries goes to 0, the internal plates can warp. When that happens they can short out cells. A shorted battery cell is like trying to swim with a great white in a kiddie pool. You're not going to like what happens. Get the battery, I doubt the dealer will give you a break on price. I have the red top Optima. Seems to be working nicely.
Elmer
Elmer
We made that battery and when I lived in Detroit, my engineers took batteries apart every week to see why they failed.
I have Optima Yellow tops in my Corvette, Acura and pickup. Don't have one in my other car because it won't fit.
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
Costco batteries have given me great service, having used them in several cars, and the price is hard to match. I just put a 100 month warranty Costco in my 06 Corvette for $66. Works great and is a free exchange (no proration) for the first 36 months. Hard to beat. Same cranking power as the original Delco. 
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
When one of these batteries goes to 0, the internal plates can warp. When that happens they can short out cells. A shorted battery cell is like trying to swim with a great white in a kiddie pool. You're not going to like what happens. Get the battery, I doubt the dealer will give you a break on price. I have the red top Optima. Seems to be working nicely.
Elmer
Elmer
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
In choosing battery, external physical attribute on a given size plays a big part in terms of strength and capacity! Such as rounded external (less capacity) verse square cornered (more capacity).
Optima has rounded external shell, in addition, from previous experiences, Optima durability is not the same as the past - maybe source of manufacturing has something to do with that!
***Optima has different Warranty for Hawaii (Shorter) - I wonder why?
On the other hand, although expensive, Odyssey is also AGM type, built stout enough to passed Military Specifications - that is a testimony in itself!
---Odyssey's warranty is the same for Hawaii as the rest of the world! Anyone wonders whys?
Optima has rounded external shell, in addition, from previous experiences, Optima durability is not the same as the past - maybe source of manufacturing has something to do with that!
***Optima has different Warranty for Hawaii (Shorter) - I wonder why?
On the other hand, although expensive, Odyssey is also AGM type, built stout enough to passed Military Specifications - that is a testimony in itself!
---Odyssey's warranty is the same for Hawaii as the rest of the world! Anyone wonders whys?
Who told you it was shorter?
Optima also passes military specs. The drop Optimas out of airplanes in generators and such. They are our largest customer!
Team Owner
Joined: Feb 2000
Posts: 53,529
Likes: 77
From: Arizona
First off, many thanks to johnodrake for the window re-indexing instructions. I had no idea this was something I could do myself. Next, I'm positive I did not forget to shift into reverse when parking. The car dings at you anyway when you open the door if it isn't in reverse. And thanks also to spartan 45 for telling me about the column lock bypass. I'm going to look into that too.
The more I think about it, the more it seems like it is must be the battery. What gets me though is that I've had bad batteries in the past and they always give some warning before they die, like slow cranking down to nothingness. This is the first time I've ever seen a battery go from hero to zero in one day that wasn't caused by some external drain. Thanks also to timd38 for the kind offer to check the battery, but I'm in NY which is a bit of a trip. Supposedly the dealer tested it anyway.
Now, I'll grant that it is the original battery and it did get drained once before, last year when it was stored for the winter and my float charger died. I'd just go ahead and put in a new one, but since I already took it to the dealer last week it's his problem now. We'll see what he has to say tomorrow.
The more I think about it, the more it seems like it is must be the battery. What gets me though is that I've had bad batteries in the past and they always give some warning before they die, like slow cranking down to nothingness. This is the first time I've ever seen a battery go from hero to zero in one day that wasn't caused by some external drain. Thanks also to timd38 for the kind offer to check the battery, but I'm in NY which is a bit of a trip. Supposedly the dealer tested it anyway.
Now, I'll grant that it is the original battery and it did get drained once before, last year when it was stored for the winter and my float charger died. I'd just go ahead and put in a new one, but since I already took it to the dealer last week it's his problem now. We'll see what he has to say tomorrow.
Dead Battery Syndrome.
If it has been reflashed then the Column Lock Bypass is a definite. If not the reflash might suffice for an unknown amount of time. I'd recommend both and be done with it.
Racer
Joined: Feb 2009
Posts: 425
Likes: 0
From: Diamondhead Mississippi
My original ac delco battery lasted 7 years, just replaced it last week. Car sat for 8 months with no battery tender or anything. I jump started it and it worked fine. The only reason I had to replace it is because the negative post was worn out and wouldn't give a good contact.
Hit and miss id say.
Hit and miss id say.